0000035315 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundClassK6Pro07Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundRetailPRO14Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member bmp:C000048838Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member bmp:C000048841Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member bmp:C000048840Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member bmp:C000048842Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundAMCIZPRO21Member bmp:S000017675Member bmp:C000205021Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundClassK6Pro07Member bmp:S000017675Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundClassK6Pro07Member bmp:S000017675Member bmp:C000214978Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundRetailPRO14Member bmp:S000017675Member 2021-11-29 2021-11-29 0000035315 bmp:D0930FidelityStrategicRealReturnFundRetailPRO14Member bmp:S000017675Member bmp:C000048837Member 2021-11-29 2021-11-29 iso4217:USD pure 497 2021-09-30 false 0000035315 N-1A FIDELITY SALEM STREET TRUST Supplement to theFidelity® Strategic Real Return FundClass A, Class M, Class C, Class I and Class ZNovember 29, 2021Prospectus  Annual Operating Expenses (expenses that you pay each year as a % of the value of your investment) 0.0055 0.0055 0.0055 0.0055 0.0055 0.0025 0.0025 0.0100 0 0 0.0031 0.0032 0.0033 0.0028 0.0018 0.0111 0.0112 0.0188 0.0083 0.0073 -0.0016 -0.0017 -0.0018 -0.0013 -0.0012 0.0095 0.0095 0.0170 0.0070 0.0061 January 31, 2024 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares: 493 493 493 493 273 173 72 72 62 62 702 702 703 703 549 549 233 233 204 204 951 951 954 954 976 976 430 430 377 377 1664 1664 1673 1673 1964 1964 996 996 879 879 Using a neutral mix of approximately 25% inflation-protected debt securities (which attempts to track the Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index, an index composed of inflation-protected debt securities issued by the U.S. Treasury), 25% floating rate loans, 30% commodity-linked derivative instruments and related investments, and 20% REITs and other real estate related investments. Supplement to theFidelity® Strategic Real Return FundClass K6November 29, 2021Prospectus  Annual Operating Expenses (expenses that you pay each year as a % of the value of your investment) 0.0055 0 0.0014 0.0069 -0.0018 0.0051 January 31, 2024 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 52 177 341 817 Using a neutral mix of approximately 25% inflation-protected debt securities (which attempts to track the Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index, an index composed of inflation-protected debt securities issued by the U.S. Treasury), 25% floating rate loans, 30% commodity-linked derivative instruments and related investments, and 20% REITs and other real estate related investments. Supplement to theFidelity® Strategic Real Return FundNovember 29, 2021Prospectus  Annual Operating Expenses (expenses that you pay each year as a % of the value of your investment) 0.0055 0 0.0030 0.0085 -0.0015 0.0070 January 31, 2024 This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that your shareholder fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated: 72 235 436 1015 Using a neutral mix of approximately 25% inflation-protected debt securities (which attempts to track the Bloomberg U.S. Treasury Inflation-Protected Securities (TIPS) Index, an index composed of inflation-protected debt securities issued by the U.S. Treasury), 25% floating rate loans, 30% commodity-linked derivative instruments and related investments, and 20% REITs and other real estate related investments. (a)Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse Class A, Class M, Class C, Class I, and Class Z of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund’s securities lending program, if applicable), as a percentage of their respective average net assets, exceed 0.95%, 0.95%, 1.70%, 0.70%, and 0.61% (the Expense Caps). If at any time during the current fiscal year expenses for Class A, Class M, Class C, Class I, or Class Z of the fund fall below the Expense Caps, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Caps. These arrangements will remain in effect through January 31, 2024. FMR may not terminate these arrangements before the expiration date without the approval of the Board of Trustees and may extend them in its discretion after that date. (a)Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse Class K6 of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund’s securities lending program, if applicable), as a percentage of its average net assets, exceed 0.51% (the Expense Cap). If at any time during the current fiscal year expenses for Class K6 of the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through January 31, 2024. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date. (a)Fidelity Management & Research Company LLC (FMR) has contractually agreed to reimburse the class of shares of the fund to the extent that total operating expenses (excluding interest, certain taxes, fees and expenses of the Independent Trustees, proxy and shareholder meeting expenses, extraordinary expenses, and acquired fund fees and expenses (including fees and expenses associated with a wholly owned subsidiary), if any, as well as non-operating expenses such as brokerage commissions and fees and expenses associated with the fund’s securities lending program, if applicable), as a percentage of its average net assets, exceed 0.70% (the Expense Cap). If at any time during the current fiscal year expenses for the class of shares of the fund fall below the Expense Cap, FMR reserves the right to recoup through the end of the fiscal year any expenses that were reimbursed during the current fiscal year up to, but not in excess of, the Expense Cap. This arrangement will remain in effect through January 31, 2024. FMR may not terminate this arrangement before the expiration date without the approval of the Board of Trustees and may extend it in its discretion after that date.