Filed under Rule 424(b)(2), Registration Statement No. 333-226651

Preliminary Pricing Supplement No. 259 - Dated Tuesday, June 1, 2021 (To: Prospectus dated August 7, 2018)

CUSIP

Principal

Selling

Gross

Net

Coupon

Coupon

Coupon

Maturity

1st Coupon

1st Coupon

Survivor's

Product

Number

Amount

Price

Concession

Proceeds

Type

Rate

Frequency

Date

Date

Amount

Option

Ranking

02006DXP1

[]

100.000%

0.825%

[]

Fixed

0.600%

Monthly

06/15/2024

07/15/2021

$0.58

Yes

Senior Unsecured Notes

Redemption Information: Callable at 100% on 12/15/2021 and Semi-Annually thereafter with 30 Calendar Days' Notice.

02006DXQ9

[]

100.000%

1.250%

[]

Fixed

1.300%

Monthly

06/15/2026

07/15/2021

$1.26

Yes

Senior Unsecured Notes

Redemption Information: Callable at 100% on 12/15/2021 and Semi-Annually thereafter with 30 Calendar Days' Notice.

Ally Financial Inc. Offering Date: Tuesday, June 1, 2021 through Monday, June 7, 2021 Trade Date: Monday, June 7, 2021 @ 12:00 PM ET Settle Date: Thursday, June 10, 2021 Minimum Denomination/Increments:$1,000.00/$1,000.00 Initial trades settle flat and clear SDFS: DTC Book Entry only DTC Number 0235 via RBC Dain Rauscher Inc   Agents: Incapital LLC, Citigroup, RBC Capital Markets, Morgan Stanley, J.P. Morgan, Wells Fargo Advisors, LLC   If the maturity date or an interest payment date for any note is not a business day (as term is defined in prospectus), principal, premium, if any, and interest for that note is paid on the next business day, and no interest will accrue from, and after, the maturity date or interest payment date. Ally Financial Inc. Ally Financial Term Notes, Series A Prospectus dated August 7, 2018