Quarterly Investor Relations Presentation At and for the three and nine months ended June 30, 2016

About GWB 2 Company Snapshot Exchange / Ticker • NYSE: GWB Market Cap • 58.7 million shares outstanding / $2.03 billion Ownership • 100% publicly traded Total Assets • $11.45 billion ROA / ROTCE • 1.16% / 15.0% FYTD Efficiency Ratio • 50.0% FYTD; quarterly ratio elevated due to $12.2 million of one-time acquisition expenses FTEs • Approximately 1,600 Locations • 178 branches in nine states Business & Ag Expertise • 87% of loans in business and ag segments; 8 th largest farm lender bank in the U.S.(1) (1) As of March 31, 2016. Source: FDIC. NOTE: All financial data is as of or for the three months ended June 30, 2016 unless otherwise noted. Market Cap calculated based on July 15, 2016 closing price of $34.61. Branch count as of July 28, 2016. See appendix for non-GAAP reconciliation of ROTCE and efficiency ratio.

Footprint 3 • 178 banking branches across nine Midwestern and Western states(1) • Vibrant, diverse economies balanced across growing commercial hub cities and smaller rural communities • Opportunities for expansion into new markets within and adjacent to footprint Attractive Markets (1) Branch count as of July 28, 2016

• FYTD net charge-offs of 0.08% of average loans compared to 0.17% in comparable FY15 period • Deterioration of a small number of loan relationships led to an increase in nonaccrual loans during the quarter; each has been monitored and managed over a number of quarters Executing on Strategy Focused Business Banking Franchise with Agribusiness Expertise • Loan balances increased by $1.28 billion, or 17.5%, compared to September 30, 2015 • Includes $863.7 million of acquired loans; organic FYTD net growth of 5.7% • Lending growth continues to be focused in CRE, C&I and Ag portfolio segments • Deposit balances increased by $1.09 billion, or 14.8%, from September 30, 2015 • Includes $863.1 million of acquired deposits • The HF Financial Corp. acquisition added 23 new branches and a new presence in ND and MN Strong Profitability and Growth Driven by a Highly Efficient Operating Model • Fully diluted EPS of $0.46 for the quarter compared to $0.50 for 3QFY15; adjusted EPS excluding one-time acquisition expenses of $0.59 per share • Strong FYTD profitability metrics: 1.16% ROAA and 15.0% ROATCE(1) for FYTD • Efficiency ratio(1) of 58.8% for the quarter compared to 46.4% for 3QFY15, elevated because of one-time HF Financial Corp acquisition expenses Risk Management Driving Strong Credit Quality Strong Capital Generation and Attractive Dividend • All regulatory capital ratios remain above minimums to be considered “well capitalized” • Quarterly dividend of $0.14 per share announced July 28, 2016; payable August 24, 2016 to stockholders of record as of the close of business on August 12, 2016 (1) This is a non-GAAP measure. See appendix for reconciliation. 3

Experienced Management Team • Prior experience – Senior Human Resource Generalist for Citibank and Wells Fargo 37 39 33 25 22 16 32 27 7 14 9 7 15 12 26 2 Ken Karels President and CEO Doug Bass Regional President • Regional President for Iowa / Kansas / Missouri, Arizona / Colorado, L&D / Marketing, Operations, and People & Culture • Prior positions with U.S. Bank and First American Bank Group Bryan Kindopp Regional President • Regional President for Nebraska and South Dakota • Prior role overseeing branch operations – northeastern South Dakota Pete Chapman Executive VP & CFO • Responsible for financial / regulatory reporting, planning and strategy, project management, and treasury • Prior U.S. experience with E&Y Steve Ulenberg Executive VP & CRO • Responsible for risk framework across Great Western • Prior leadership roles in commercial and wholesale banking, risk management, and cross-organizational strategy – National Australia Bank Executive Officers • Former COO and Regional President – Great Western • Former President and CEO – Marquette Bank • Prior experience – VP & Regional Training Manager for Bank of the West and VP Learning and Development Officer for Community First Bankshares Inc Cheryl Olson Head of L&D and Marketing Industry experience (yrs) Great Western Bank experience (yrs) (1) Andy Pederson Head of People & Culture Donald Straka General Counsel • Prior experience – attorney and executive in banking, securities and M&A Non-Executive Officers 5(1) For Messers. Chapman and Ulenberg, includes experience at National Australia Bank, Ltd. and subsidiaries

HF Financial Corp. Acquisition Update 6 Highlights Financial Targets • GWB completed the acquisition of HF Financial Corp. and Home Federal Bank on May 16, 2016 • Added total assets of $1.1 billion including $863.7 million of loans • Acquired deposits of $863.1 million • Systems conversion completed over the weekend of June 10-12, 2016, with no significant issues arising • Gained 23 branch locations and exciting new market presence in eastern North Dakota and Minnesota • 5 GWB and HFB branch locations have been identified for closure in August 2016 following regulatory notice period • Integration of former Home Federal Bank customers and employees progressing favorably At Deal Announcement Current Update Cost synergies 40% reduction to HF’s core noninterest expense base; 70% achieved in FY16 Ahead of pace to achieve announced synergies One-time acquisition expenses ~$25 million ~$13 million expensed through June 30, 2016; majority of costs have been incurred EPS accretion ~6% accretive to FY17 EPS No material changes to expectation TBV / share dilution and earnback ~1% dilution and earnback of less than 3 years TBV / share increased from $14.58 at March 31 to $15.15 at June 30 Capital ratios ~40-50 bps impact to Tier 1 and Total Capital Ratios In line with expectations

Acquisition History Acquired Security Bank ($0.1 billion) Acquired Sunstate Bank and three branches from HF Financial Corp. ($0.2 billion total) Acquired F&M Bank-Iowa and TierOne Bank ($3.0 billion total) Acquired North Central Bancshares Inc. ($0.4 billion) Asset CAGR ‘09 – ‘16: 12% Note: Total assets are as of September 30 of each fiscal year unless otherwise noted. Acquired assets are the total of the fair value of total assets acquired and the net cash and cash equivalents received, at the time of acquisition of each indicated year. 7 Acquired First Community Bank’s Colorado franchise and a branch from Wachovia ($0.6 billion total) $3.1 $3.4 $4.3 $5.2 $8.3 $8.2 $9.0 $9.1 $9.4 $9.8 $11.5 $0.0 $1.0 $2.0 $3.0 $4.0 $5.0 $6.0 $7.0 $8.0 $9.0 $10.0 $11.0 $12.0 '06 '07 '08 '09 '10 '11 '12 '13 '14 '15 3Q '16 Pre-Acquisition Assets Acquired Assets Acquired HF Financial ($1.1 billion total)

Commercial non- real estate, 20.2% Ag real estate, 11.6% Ag operating, 12.7%Construction & development, 5.6% Owner-occupied CRE, 14.0% Non owner- occupied CRE, 17.9% Multifamily, 4.7% Residential real estate, 11.9% Consumer, 0.9% Other, 0.5% $923 $1,092 $1,396 $1,587 $1,681 $1,861 $2,102 $959 $971 $1,354 $1,482 $1,571 $1,611 $1,746 $2,544 $2,342 $2,364 $2,312 $2,541 $2,846 $3,657 $993 $777 $940 $906 $902 $922 $1,032 $192 $111 $143 $126 $124 $111 $125 $5,610 $5,293 $6,197 $6,414 $6,820 $7,351 $8,662 FY10 FY11 FY12 FY13 FY14 FY15 3QFY16 Agriculture C&I Commercial RE Residential RE Consumer and Other Loan Portfolio Composition 8 Loan Portfolio ($MM) At September 30 of each fiscal year unless otherwise noted (UPB). Portfolio Segmentation by Type Geographic Diversification Focused business and ag lending growth Iowa / Kansas / Missouri 29% South Dakota 29% Nebraska 17% Arizona / Colorado 20% Minnesota / North Dakota 2% Other 3%

$(1.6) $(0.3) $(5.6) $0.5 $1.0 $2.1 $(1.6) $0.2 $(3.3) $0.9 $(6.0) $(5.0) $(4.0) $(3.0) $(2.0) $(1.0) $- $1.0 $2.0 $3.0 2012 2013 2014 2015 FY16 YTD ASC 310-30 Non ASC 310-30 Additional Loan Information 9 Comprehensive Credit Coverage ($M) Incremental Impact from Acquired Loans ($MM)Highlights GWB Legacy - Loans at Amortized Cost GWB Legacy - Loans at Fair Value HF Financial Corp. Acquired Loans Other Acquired Loans Total ALLL 58,069$ -$ -$ 6,174$ 64,243$ Remaining Loan Discount -$ -$ 27,002$ 15,791$ 42,793$ Fair Value Adjustment (Credit) -$ 8,060$ -$ -$ 8,060$ Total ALLL/Discount/FV Adj. 58,069$ 8,060$ 27,002$ 21,965$ 115,095$ Total Loans 6,361,011$ 1,156,442$ 852,226$ 237,295$ 8,606,974$ ALLL / Total Loans 0.91% - - 2.60% 0.75% Discount / Total Loans - - 3.17% 6.65% 0.50% FV Adj. / Total Loans - 0.70% - - 0.09% Total Coverage / Total Loans (1) 0.91% 0.70% 3.17% 9.26% 1.34% (1) Non-GAAP measure that Management believes is useful to demonstrate that the FV adjustments related to credit and remaining loan discounts consider credit risk and should be considered as part of total coverage. • Loan portfolio is managed to Board-approved concentration limits • All categories are currently within limits with ample room for future growth • Income statement impact from acquired loans (including indemnification asset amortization) has not significantly inflated earnings and is not expected to in the future • Management remains very comfortable with credit coverage levels Includes ASC 310-20 accretion, ASC 310-30 accretion in excess of contractual interest and indem. asset amortization

Elevated Expenses Straining Profitability (1) Ag Economy 10 Highlights • Industry has strong balance sheets with debt/equity and debt/assets well below long-term average levels • Many producers have the ability to withstand lower profitability – cash flow versus solvency • Elevated expenses resulting from high land (purchase and cash rent) and energy costs are forecast to move downward, restoring more normalized profitability • USDA projects net farm income to bottom out in 2016 and then gradually return to a modest growth trajectory Industry Debt/Equity Ratio (1) Projected Farm Net Income (1) (1) Source: USDA Economic Research Service, historical actuals and projections through 2025 for the entire US agricultural sector.

Ag Lending 101 11 • Underwriting fundamentals are identical to comparable C&I and CRE businesses • Cash flow is the primary source of repayment • Collateral is the secondary source of repayment • Advance rates on lines and amount of term debt subject to LTV limits and collateral values based on “normalized” valuations • Liquid markets typically exist for ag-related collateral (e.g. harvested grain or grain inventory, cattle, farm equipment and land sale/lease) in foreclosure scenarios • Federally-subsidized crop insurance and FSA guarantees are two examples of risk mitigants unique to ag lending • A number of market and economic conditions can be leading indicators for individual borrowers and are monitored by GWB; none are broadly indicative for GWB’s ag portfolio as a whole: • Interest rates, economic growth and policy • Farm leverage ratios • Weather and drought conditions • Disease • Commodity prices – corn, soybeans, cattle, hogs, milk, cheese, etc. • Yields Highlights Grain vs Protein – A Natural “Hedge” Protein farmers tend to do better when grain prices (feed) are low and demand for protein outputs are high; global demand will influence herd populations and impact downstream economics. Grain farmers have come under some revenue pressure (commodity prices); depressed revenue will drive costs down and/or marginal producers out of business. Customers are generally well positioned to sustain lean years with low debt and strong crop conditions. Deal Structure Short Term Operating (Typically 1-2 Years) •Operational / working capital subject to borrowing base requirements •$881 million at Jun 30, 2016 Medium Term (Typically 3- 5 Years) •Machinery / equipment and livestock subject to LTV guidelines of 50-75% depending on asset class •$337 million at Jun 30, 2016 Real Estate Loans (Typically 5-15 Years with Amortization) •Valuation based on 3rd Party appraisals; 70% max LTV guideline •$871 million at Jun 30, 2016

Avg. of All Farms Low 20% Profitability High 20% Profitability Avg. of All Farms Low 20% Profitability High 20% Profitability Number of farms 95 19 19 70 14 14 Yield - bushels (1) 152.51 134.65 173.00 152.28 114.99 177.55 Sale price (2) 3.40$ 3.33$ 3.47$ 3.37$ 3.31$ 3.53$ Revenue: Gross corn revenue (1)*(2) 518.53$ 448.38$ 600.31$ 513.18$ 380.62$ 626.75$ Crop insurance 24.36 10.29 13.49 15.60 3.52 1.98 Other revenue 24.08 26.61 15.59 30.50 44.07 30.47 Total revenue 566.97 485.28 629.39 559.28 428.21 659.20 Direct expenses: Land rent 151.49 231.89 112.34 - - - Fertilizer 116.67 104.23 104.43 99.74 98.53 73.63 Seed 92.03 87.48 79.52 84.47 84.03 77.49 Crop insurance 25.84 23.12 21.38 24.78 22.17 11.50 Chemicals 39.94 65.88 37.38 40.81 48.25 36.99 Fuel 24.35 29.69 22.21 24.06 29.30 19.97 Other direct expenses 56.08 74.14 45.53 58.26 86.80 31.21 Total direct expenses 506.40 616.43 422.79 332.12 369.08 250.79 Overhead expenses: Depreciation 43.14 60.38 32.56 54.16 65.74 36.25 Real estate taxes 0.62 1.62 0.37 30.85 31.31 46.81 Interest 2.97 2.76 2.23 35.35 65.74 36.25 Other overhead expenses 44.36 75.13 38.05 41.56 45.34 47.71 Total overhead expenses 91.09 139.89 73.21 161.92 208.13 167.02 Net return per acre (30.52)$ (271.04)$ 133.39$ 65.24$ (149.00)$ 241.39$ Total cost per bushel 3.92 5.62 2.87 3.24 5.02 2.35 Source: FINBIN - University of Minnesota Farms in Nebraska and South Dakota - 2014 Production Year Corn on Cash Rent Corn on Owned Land Summary Farm Income Statement - Per Acre Example Farm Income Statement 12 Key Takeaways • Wide range of outcomes across both revenue and expense categories – partnering with experienced producers with strong balance sheets is key • Average revenue similar between renters and owners but renters’ total cost per bushel was 21% higher, the difference between positive and negative net return • The most profitable producers achieve better yields (i.e., more revenue) with lower input costs – prudent management, better cost control and more productive land • Crop insurance is a very affordable risk management tool – small portion of total cost base • USDA forecasts grain prices to stabilize while costs will decrease from 2014 levels, especially land rent, fuel and fertilizer – this should lead to better average profitability

$15M+ 10.3% $5M- $15M 34.4% $1M - $5M 30.9% $250K - $1M 15.8% <$250K 8.6% Ag Loan Portfolio 13 Highlights Ag Portfolio Composition by Industry (UPB) Ag Net Charge-offs / Average Loans (1) ($MM)Ag Portfolio Exposure Sizes (UPB) NOTE: All customer references are aggregated based on CIF and do not group CIFs with related ownership groups. Industry disclosures based on NAICS codes. (1) Net charge-offs / average loans represent charge-offs, net of recoveries, as a percent of average loans for each period. Average loans are calculated as the two point average of each period. • Portfolio balanced across subsegments • 10 largest Ag exposures represent 9.5% of total Ag and average $20.0 million • Approximately 3,500 customers with an average exposure size of $598,674 • Grain producer portfolio review completed in spring 2016 concluded that most producers have low LTVs and low leverage Grains, 36% Beef Cattle, 26% Dairy Farms, 18% Hogs, 6% Cotton, 2% Other Specialty, 12% Grains 36% Proteins 50% Other 14% 0.1% (0.0)% 0.3% 0.1% 0.0% 0.4% FY11 FY12 FY13 FY14 FY15 FYTD16 $0.87 ($0.11) $4.05 $2.37 $0.48 $1.87

0.9% 0.5% 0.2% 0.3% 0.5% 0.3% FY11 FY12 FY13 FY14 FY15 FYTD16 $15M+ 28.2% $5M- $15M 23.8% $1M - $5M 26.1% $250K - $1M 12.7% <$250K 9.2% 8.0% 4.8% 4.0% 3.8% 4.1% 0.4% 3.5% 4.8% 66.6% Med / Surg Hospitals Casino Hotels Trucking Retirement Communities Residential Warehouse Lending Lessors of Residential Buildings and Dwellings Farm and Garden Equip Wholesalers Nursing Care Facilities Other Diverse C&I Exposure 14 Highlights C&I Portfolio Composition by Industry (UPB) C&I Portfolio Exposure Sizes (UPB) C&I Net Charge-offs / Average Loans (1) ($MM) NOTE: All customer references are aggregated based on CIF and do not group CIFs with related ownership groups. Industry disclosures based on NAICS codes. (1) Net charge-offs / average loans represent charge-offs, net of recoveries, as a percent of average loans for each period. Average loans are calculated as the two point average of each period. • Diverse range of industry exposure across C&I lending portfolio, including healthcare, tourism & hospitality, freight & transport and agribusiness-related services • No significant energy-related exposure, 1.2% of total loans • 10 largest C&I exposures represent 21.2% of total C&I and average $37 million • Approximately 4,400 customers with an average exposure of $389,309 $8.33 5.92 $2.43 $3.94 $7.75 $1.32

$15M+ 14.0% $5M- $15M 36.1% $1M - $5M 35.0% $250K - $1M 11.5% <$250K 3.4% Construction and development $501.2 13.7% Owner-occupied CRE $1,207.7 32.9% Non-owner- occupied CRE $1,554.1 42.3% Multifamily $408.0 11.1% Focused CRE Lending 15 Highlights CRE Portfolio Composition by Type (UPB $MM) CRE Portfolio Exposure Sizes (UPB) CRE Net Charge-offs / Average Loans (1) ($MM) NOTE: All customer references are aggregated based on CIF and do not group CIFs with related ownership groups. Industry disclosures based on NAICS codes. (1) Net charge-offs / average loans represent charge-offs, net of recoveries, as a percent of average loans for each period. Average loans are calculated as the two point average of each period. • Focus on owner-occupied properties, commercial property investors, multi-family property investors and a diverse range of commercial construction with limited exposure to land development and other speculative projects • Continued customer demand to finance CRE development, especially in larger markets in footprint • 10 largest CRE exposures represent 7.1% of total CRE and average $25.6 million 1.3% 0.9% 0.8% 0.1% 0.0% 0.1% FY11 FY12 FY13 FY14 FY15 FYTD16 $32.10 $21.59 $18.96 $1.73 $0.63 $0.50

FHLB & Other Borrowings - 0.66% WA Cost Securities sold under agreements to repurchase - 0.33% WA Cost Subordinated debentures and subordinated notes payable - 3.87% WA Cost U.S. Treasuries 17% U.S. Agencies 4% GNMA 52% Other MBS 24% States and political subdivisions 3% Corporate debt 0% Investments & Borrowings 16 • Recent reinvestments have continued to transition to a portfolio composition more similar to U.S. peers over time • Investment portfolio weighted average life of 3.0 years as of June 30, 2016 and yield of 1.84% for the quarter ended June 30, 2016, an increase of 4 basis points compared to the prior quarter • Borrowings portfolio had a cost of 0.98% for the quarter ended June 30, 2016 Investment Portfolio Borrowings & Weighted Average Cost Highlights

Iowa / Kansas / Missouri 29.7% South Dakota and Other 26.7% Nebraska 27.8% Arizona / Colorado 15.4% North Dakota / Minnesota 0.4% Non-interest- bearing demand 21.3% NOW, MMDA and savings 61.9% Time certificates $250K+ 3.0% Other time certificates 13.8% Deposits 17 Portfolio Segmentation by Type Portfolio Over Time ($MM) Geographic Diversification NOTE: South Dakota and Other deposits include a small amount of deposits managed by our Corporate staff. Portfolio transformation away from time deposits and significant business deposit growth At September 30 of each fiscal year unless otherwise noted. $848 $1,076 $1,199 $1,303 $1,368 $1,802 $2,532 $3,037 $3,602 $4,005 $4,638 $5,252 $2,891 $2,771 $2,147 $1,744 $1,380 $1,426 $6,272 $6,885 $6,948 $7,052 $7,387 $8,480 FY11 FY12 FY13 FY14 FY15 3QFY16 Non-interest-Bearing Interest-Bearing Demand Time

Tangible equity net of DTAs and AOCI, $895.1 , 84% Eligible trust- preferred securities, $77.1 , 7% Eligible ALLL, $64.2 , 6% Eligible subordinated debt, $35.0 , 3% Capital 18 Summary Excess Capital Priorities Capital Ratios Total Capital Composition ($MM) • Attractive dividend of $0.14 quarterly (yield of 1.8% based on avg. closing price during the quarter) (1) • All regulatory capital ratios remain above regulatory minimums to be considered “well capitalized” • Strong relationships with regulators at holding company and bank level (1) Future dividends subject to Board approval Attractive Acquisitions Share Buybacks Increased / Special Dividends 1 2 3 Ratio Well Capitalized Minimum Difference to Well Capitalized Tier 1 capital 10.9% 8.0% 2.9% Total capital 12.0% 10.0% 2.0% Tier 1 leverage 10.0% 5.0% 5.0% Common equity tier 1 10.0% 6.5% 3.5% Tangible common equity / tangible assets 8.3% - - Risk-weighted assets ($MM) 8,986$ Ratio Well Capitalized Minimum Difference to Well Capitalized Tier 1 capital 11.1% 8.0% 3.1% Total capital 11.8% 10.0% 1.8% Tier 1 leverage 10.1% 5.0% 5.1% Common equity tier 1 11.1% 6.5% 4.6% Risk-weighted assets ($MM) 8,992$ Great Western Bancorp, Inc. Great Western Bank

Fixed, $3,188 , 37% Fixed (swapped), $1,073 , 13% Floating (no floor), $3,165 , 37% Floating (floor), $1,123 , 13% Other, $(24), 0% -2.00% 0.00% 2.00% 4.00% 6.00% 8.00% 10.00% 12.00% 14.00% -100 bps +100 bps +200 bps +300 bps +400 bps Estimated Increase (Decrease) in Annualized Adjusted Net Interest Income Immediate Gradual Interest Rate Sensitivity 19 Summary Loan Portfolio Behavior ($MM) Sensitivity Modeling • Average floor is 72 bps out of the money • Floating: 59% Prime, 22% 5yr Tsy, 19% all other • Management believes the balance sheet is well-prepared for a range of interest rate actions, but is modestly asset sensitive • Internal budgeting and planning assumes a flat rate environment with any lift from rate increases viewed as potential upside • Investment portfolio weighted average life of 3.0 years • Relatively short average tenor of the loan portfolio (1.3 years at June 30, 2016) due to: • Higher proportion of 12-month revolving lines of credit in line with business and agriculture lending focus • Certain fixed-rate loans with original terms greater than 5 years are swapped to floating

$219 $288 $310 $396 $139 $126 $184 $238 $358 $414 $494 $634 5.6% 6.1% 6.7% 7.4% FY13 FY14 FY15 3Q FY16 Watch Loans Substandard Loans % of Total Loans Asset Quality 20 Highlights Net Charge-offs / Average Total Loans Strong Credit QualityWatch & Substandard Loans ($MM) • Ratio of ALLL / total loans was 0.75% at June 30, 2016 compared to 0.82% at March 31, 2016 and 0.77% at June 30, 2015, with the reduction primarily a result of acquiring loans during the quarter with no carryover of ALLL • Nonaccrual loans increased by $53.2 million during the quarter primarily due to a small number of known exposures that had already been identified as “Substandard” • Loans graded “Watch” and “Substandard” increased $62.3 million and $15.4 million, respectively, during the quarter 0.27% 0.65% 0.88% 0.54% 0.44% 0.14% 0.13% 0.08% FY09 FY10 FY11 FY12 FY13 FY14 FY15 3Q FY16 (Ann.) 2.76% 2.03% 1.16% 0.93% 1.26% 42.4% 43.3% 60.2% 83.8% 59.4% FY12 FY13 FY14 FY15 3Q FY16 NALs / Total Loans Reserves/NALs Quarterly increase in Watch and Substandard loans driven by acquired loans

$- $2.0 $4.0 $6.0 $8.0 $10.0 $12.0 $14.0 $16.0 $18.0 $20.0 $- $5.0 $10.0 $15.0 $20.0 $25.0 $30.0 $35.0 $40.0 $45.0 $50.0 Year-end balance (left axis) Annual amortization (right axis) Goodwill & Intangible Assets 21 Goodwill ($MM) Other Intangible Assets ($MM) (1) (1) Balances and amortization expense at September 30 and for the respective fiscal years. Amounts for fiscal years 2016 – 2018 are forecast based on existing intangible assets and could change materially based on future acquisitions. • Majority (84%) of goodwill on GWB’s balance sheet resulted from the acquisition of GWB by NAB and was pushed down to GWB’s balance sheet • Recognizing an impairment, which management does not currently believe exists, is the only opportunity to eliminate the “inherited” goodwill • Existing intangible assets and related amortization have become minimal • Future M&A activity could generate additional assets and amortization expense NAB acquisition of GWB $622.4 HF Financial, $40.7 GWB acquisitions pre-IPO $75.4

Income Statement Summary

3.95% -0.02% -0.04% -0.01% 3.99% 0.02% 0.01% $86.2 $93.6 3.95% 3.95% 3.92% 3.97% 3.70% 3.74% 3.67% 3.74% 3Q FY15 3Q FY16 FY 15 YTD FY 16 YTD Net Interest Income (FTE) NIM (FTE) Adjusted NIM (FTE) (1) Chart excludes changes related to loans and derivatives at fair value which netted $(7.7) million for the quarter. Dollars in thousands. (2) Adjusted NIM (FTE) is a non-GAAP measure. See appendix for reconciliations. Revenue 23 Revenue Highlights Net Interest Income ($MM) and NIM NIM Analysis Noninterest Income (1) (2) • Net interest income (FTE) increased by 9% compared to 3QFY15 driven primarily by a 9% increase in average interest earning assets between the two periods • NIM (FTE) remained steady at 3.95% and adjusted NIM (FTE) (2) was 4 basis points higher compared to 3QFY15, primarily as a result of changes in asset mix • Noninterest income decreased 9% compared to 3QFY15, primarily driven by credit charges related to loans at FV • Service charges and other fees increased by $2.7 million driven primarily by higher interchange income Service charges and fees, $12,316 Wealth management fees, $1,807 Mortgage banking income, net, $1,669 Gain on security sales, $134 Other, $898 $252.9 $269.5

$49.0 $137.4 $12.2 $12.9 $46.4 $61.2 $142.0 $150.3 46.4% 58.8% 48.8% 50.0% 3Q FY15 3Q FY16 FY15 YTD FY16 YTD Noninterest expense Acquisition expense Efficiency Ratio Expenses, Provision & Earnings 24 Highlights Provision for Loan Losses ($MM) Noninterest Expense ($MM) Net Income ($MM) Total noninterest expense and efficiency ratio increases driven by one- time acquisition expenses • Efficiency ratio (1) was 58.8% for the quarter compared to 46.4% for 3QFY15 • Elevated because of $12.2 million of one-time expenses related to the HF Financial acquisition • Provision for loan losses increased 22% compared to 3QFY15; ALLL coverage decreased to 0.75%, a reduction of 2 basis points compared to June 30, 2015, resulting from acquiring loans with no carryover of ALLL. The gross ALLL increased by $2.3 million compared to March 31, 2016 $4.4 $5.4 $17.4 $11.9 3Q FY15 3Q FY16 FY15 YTD FY16 YTD $29 $34 $30 $31 $26 $75 $88 1.18% 1.38% 1.23% 1.24% 1.00% 1.04% 1.16% 3Q FY15 4Q FY15 1Q FY16 2Q FY16 3Q FY16 FY15 YTD FY16 YTD Net Income Adjusted net income ROAA(1) Efficiency ratio and adjusted net income are non-GAAP measures. See appendix for reconciliations.

Proven Business Strategy 25 Focused Business Banking Franchise with Agribusiness Expertise Risk Management Driving Strong Credit Quality Attract and Retain High-Quality Relationship Bankers Invest in Organic Growth While Optimizing Footprint Deepen Customer Relationships Strong Profitability and Growth Driven by a Highly Efficient Operating Model Strong Capital Generation and Attractive Dividend Explore Accretive Strategic Acquisition Opportunities

Forward-Looking Statements: This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Statements about Great Western Bancorp, Inc.’s expectations, beliefs, plans, predictions, forecasts, objectives, assumptions or future events or performance are not historical facts and may be forward- looking. These statements are often, but not always, made through the use of words or phrases such as “anticipates,” “believes,” “can,” “could,” “may,” “predicts,” “potential,” “should,” “will,” “estimate,” “plans,” “projects,” “continuing,” “ongoing,” “expects,” “intends” and similar words or phrases. In particular, the statements included in this press release concerning Great Western Bancorp, Inc.’s expected performance and strategy, and the interest rate environment, beyond fiscal year 2016 are not historical facts and are forward-looking. Accordingly, the forward-looking statements in this press release are only predictions and involve estimates, known and unknown risks, assumptions and uncertainties, including those related to the recently- completed merger with HF Financial Corp., that could cause actual results to differ materially from those expressed. All forward- looking statements are necessarily only estimates of future results, and there can be no assurance that actual results will not differ materially from expectations, and, therefore, you are cautioned not to place undue reliance on such statements. Any forward-looking statements are qualified in their entirety by reference to the factors discussed in the sections titled “Item 1A. Risk Factors” and "Cautionary Note Regarding Forward-Looking Statements" in Great Western Bancorp, Inc.’s Annual Report on Form 10-K for the fiscal year ended September 30, 2015, and other periodic filings with the SEC, including its Quarterly Reports on Form 10-Q for the periods ended December 31, 2015 and March 31, 2016, and all risk factors associated with the recently completed acquisition of HF Financial Corp. Further, any forward-looking statement speaks only as of the date on which it is made, and Great Western Bancorp undertakes no obligation to update any forward-looking statement to reflect events or circumstances after the date on which the statement is made or to reflect the occurrence of unanticipated events. Non-GAAP Financial Measures: This presentation contains non-GAAP measures which our management relies on in making financial and operational decisions about our business and which exclude certain items that we do not consider reflective of our business performance. We believe that the presentation of these measures provides investors with greater transparency and supplemental data relating to our financial condition and results of operations. These non-GAAP measures should be considered in context with our GAAP results. A reconciliation of these non-GAAP measures appears in our earnings release dated July 28, 2016 and in Appendix 1 to this presentation. Our earnings release and this presentation are available in the Investor Relations section of our website at www.greatwesternbank.com. Our earnings release and this presentation are also available as part of our Current Report on Form 8-K filed with the SEC on July 28, 2016. Explanatory Note: In this presentation, all financial information presented refers to the financial results of Great Western Bancorp, Inc. combined with those of its predecessor, Great Western Bancorporation, Inc. Disclosures 26

Appendix 1 Non-GAAP Measures

Non-GAAP Measures 28 At or for the 9 Months Ended 06/30/16 06/30/15 06/30/16 03/31/16 12/31/15 09/30/15 06/30/15 Adjusted net income and adjusted earnings per share: Net Income 87,495$ 75,253$ 26,360$ 30,674$ 30,461$ 33,812$ 28,832$ Add: acquisition expenses 12,950 - 12,179 771 - - - Add: tax effect at 38% (4,921) - (4,628) (293) - - - Adjusted net income 95,524$ 75,253$ 33,911$ 31,152$ 30,461$ 33,812$ 28,832$ Weighted average diluted common shares outstanding 55,993,011 57,929,188 57,176,705 55,408,876 55,393,452 56,215,947 57,959,202 Earnings per share 1.56$ 1.30$ 0.46$ 0.55$ 0.55$ 0.60$ 0.50$ Adjusted earnings per share - diluted 1.71$ 1.30$ 0.59$ 0.56$ 0.55$ 0.60$ 0.50$ Cash net income and return on average tangible common equity: Net Income 87,495$ 75,253$ 26,360$ 30,674$ 30,461$ 33,812$ 28,832$ Add: Amortization of intangible assets 2,239 6,402 822 708 709 708 1,776 Add: Tax on amortization of intangible assets (660) (660) (220) (220) (220) (220) (220) Cash net income 89,074$ 80,995$ 26,962$ 31,162$ 30,950$ 34,300$ 30,388$ Average common equity 1,506,740$ 1,456,174$ 1,567,372$ 1,488,398$ 1,464,450$ 1,456,372$ 1,476,556$ Less: Average goodwill and other intangible assets 712,049 708,799 727,707 703,866 704,576 705,284 706,526 Average tangible common equity 794,691$ 747,375$ 839,665$ 784,532$ 759,874$ 751,088$ 770,030$ Return on average common equity 7.8% 6.9% 6.8% 8.3% 8.3% 9.2% 7.8% Return on average tangible common equity 15.0% 14.5% 12.9% 16.0% 16.2% 18.1% 15.8% At or for the 3 Months Ended

Non-GAAP Measures 29 06/30/16 06/30/15 06/30/16 03/31/16 12/31/15 09/30/15 06/30/15 Adjusted net interest income and adjusted net interest margin (fully-tax equivalent basis): Net interest income 263,947$ 248,072$ 91,652$ 86,338$ 85,957$ 85,425$ 84,538$ Add: Tax equivalent adjustment 5,522 4,798 1,905 1,791 1,826 1,778 1,704 Net interest income (FTE) 269,469 252,870 93,557 88,129 87,783 87,203 86,242 Add: Current realized derivative gain (loss) (15,832) (16,005) (5,005) (5,175) (5,652) (5,637) (5,416) Adjusted net interest income (FTE) 253,637$ 236,865$ 88,552$ 82,954$ 82,131$ 81,566$ 80,826$ Average interest-earning assets $9,061,896 $8,624,469 $9,528,576 $8,892,465 $8,764,649 $8,693,471 $8,756,244 Net interest margin (FTE) 3.97% 3.92% 3.95% 3.99% 3.98% 3.98% 3.95% Adjusted net interest margin (FTE) 3.74% 3.67% 3.74% 3.75% 3.73% 3.72% 3.70% Adjusted net interest income and adjusted yield (fully-tax equivalent basis), on Non ASC 310-30 loans: Interest income 263,930$ 244,783$ 91,829$ 86,534$ 85,567$ 84,835$ 83,094$ Add: Tax equivalent adjustment 5,522 4,798 1,905 1,791 1,826 1,778 1,704 Interest income (FTE) 269,452 249,581 93,734 88,325 87,393 86,613 84,798 Add: Current realized derivative gain (loss) (15,832) (16,005) (5,005) (5,175) (5,652) (5,637) (5,416) Adjusted interest income (FTE) 253,620$ 233,576$ 88,729$ 83,150$ 81,741$ 80,976$ 79,382$ Average Non ASC 310-30 loans $7,489,534 $6,816,785 $7,903,860 $7,371,600 $7,193,143 $7,108,598 $6,995,340 Yield (FTE) 4.81% 4.90% 4.77% 4.82% 4.83% 4.83% 4.86% Adjusted yield (FTE) 4.52% 4.58% 4.52% 4.54% 4.52% 4.52% 4.55% At or for the 9 Months Ended At or for the 3 Months Ended

Non-GAAP Measures 30 06/30/16 06/30/15 06/30/16 03/31/16 12/31/15 09/30/15 06/30/15 Efficiency Ratio: Total revenue 290,686$ 272,913$ 100,749$ 95,339$ 94,601$ 94,474$ 94,543$ Add: Tax equivalent adjustment 5,522 4,798 1,905 1,791 1,826 1,778 1,704 Total revenue (FTE) 296,208$ 277,711$ 102,654$ 97,130$ 96,427$ 96,252$ 96,247$ Noninterest expense 150,297$ 141,959$ 61,222$ 44,855$ 44,220$ 44,835$ 46,430$ Less: Amortization of intangible assets 2,239 6,402 822 708 709 708 1,776 Tangible noninterest expense 148,058$ 135,557$ 60,400$ 44,147$ 43,511$ 44,127$ 44,654$ Efficiency ratio 50.0% 48.8% 58.8% 45.5% 45.1% 45.8% 46.4% Tangible common equity and tangible common equity to tangible assets: Total stockholders' equity 1,640,511$ 1,487,851$ 1,640,511$ 1,509,202$ 1,475,516$ 1,459,346$ 1,487,851$ Less: Goodwill and other intangible assets 751,217 705,634 751,217 703,508 704,217 704,926 705,634 Tangible Common Equity 889,294$ 782,217$ 889,294$ 805,694$ 771,299$ 754,420$ 782,217$ Total Assets 11,453,222$ $9,764,159 11,453,222$ 9,942,295$ 9,957,215$ 9,798,654$ 9,764,159$ Less: Goodwill and other intangible assets 751,217 705,634 751,217 703,508 704,217 704,926 705,634 Tangible Assets 10,702,005$ 9,058,525$ 10,702,005$ 9,238,787$ 9,252,998$ 9,093,728$ 9,058,525$ Tangible common equity to tangible assets 8.3% 8.6% 8.3% 8.7% 8.3% 8.3% 8.6% Tangible book value per share: Total stockholders' equity 1,640,511$ 1,487,851$ 1,640,511$ 1,509,202$ 1,475,516$ 1,459,346$ 1,487,851$ Less: Goodwill and other intangible assets 751,217 705,634 751,217 703,508 704,217 704,926 705,634 Tangible Common Equity 889,294$ 782,217$ 889,294$ 805,694$ 771,299$ 754,420$ 782,217$ Common shares outstanding 58,693,499 57,886,114 58,693,499 55,245,177 55,244,569 55,219,596 57,886,114 Tangible book value per share 15.15$ 13.51$ 15.15$ 14.58$ 13.96$ 13.66$ 13.51$ At or for the 9 Months Ended At or for the 3 Months Ended

Appendix 2 Accounting for Loans at FV and Related Derivatives

Loans at FV and Related Derivatives 32 Overview Summary • For certain loans with an original term greater than 5 years with a fixed rate to the customer, GWB has entered into equal and offsetting fixed-to-floating interest rate swaps with two US counterparties (prior to NAB’s divestiture NAB London was the counterparty; all swaps have been novated to a US counterparty) • Total size of the portfolio was $1.16 billion at June 30, 2016 • GWB has elected the Fair Value Option (ASC 825) on these loans and applies a similar treatment to the related derivatives: • Changes in the fair value of the loans and the derivatives and the current period realized cost (benefit) of the derivatives (i.e., the net pay fixed/receive floating settlement) are recorded in earnings through noninterest income • This differs significantly from most peers who have elected Hedge Accounting treatment • The historical election is irrevocable so the concept will be present for the foreseeable future in GWB’s financial statements even if different accounting elections are made on future originations • Management presents non-GAAP measures and is including the supplemental disclosures here to provide more clarity on the underlying economics Net increase (decrease) in fair value of loans at fair value Net realized and unrealized gain (loss) on derivatives Net Relationship Notes Increase (decrease) in FV related to interest rates 16,920$ (16,920)$ -$ (1) Increase (decrease) in FV related to credit (2,722)$ -$ (2,722)$ (2) Current period realized cost of derivatives -$ (5,005)$ (5,005)$ (3) Subtotal, loans at FV and related derivatives 14,198$ (21,925)$ (7,727)$ (4) (1) (2) (3) (4) Income Statement Line Item: Management records an adjustment for credit risk in noninterest income based on loss history for similar loans, adjusted for an assessment of existing market conditions for each loan segment. The FV adjustment related to credit is not included in the ALLL but loans are included in the ALLL coverage ratio denominator. Equal and offsetting each period. Changes in the FV of each financial asset and liability driven by current compared to contractual rates. Current period actual cost of fixed-to-float interest rate swaps. Within non-GAAP financial measures, management reclassifies this component to interest income, resulting in adjusted interest income, adjusted net interest income and adjusted NIM, reflecting the underlying economics of the transactions. All else equal, this drag on earnings will reduce as short-term LIBOR rates increase. While US GAAP mandates the presentation of these items in noninterest income, management believes the residual net amount economically represents the net credit exposure of this segment of the portfolio - presented as a "credit-related charge" in the earnings release and elsewhere (see note (2)) - and the current period derivative cost which should be analyzed relative to gross interest income received from the loan customers (see note (3)) as presented in non-GAAP measures.