0000035315 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:C000261867Member 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:StockMarketVolatilityMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:ForeignAndEmergingMarketsRiskMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:GeographicExposureToAsiaMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:GeographicExposureToEuropeMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexInternationalFocusedIndexFund-PROMember fmr:S000093536Member fmr:IssuerSpecificChangesMember 2025-07-14 2025-07-14 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fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:StockMarketVolatilityMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:IssuerSpecificChangesMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:CorrelationToIndexMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:PassiveManagementRiskMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:RulesBasedStrategyRiskMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:SmallCapInvestingMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member fmr:SecuritiesLendingRiskMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member oef:RiskNotInsuredDepositoryInstitutionMember 2025-07-14 2025-07-14 0000035315 fmr:FidelityFlexMidCapFocusedandFlexSmallCapFocusedIndexFunds-ComboPROMember fmr:S000093538Member oef:RiskLoseMoneyMember 2025-07-14 2025-07-14 iso4217:USD pure shares 485BPOS 2025-07-14 false 0000035315 N-1A Fidelity Salem Street Trust Fund Summary Fund: Fidelity Flex® International Focused Index Fund Investment Objective Fidelity Flex® International Focused Index Fund seeks to provide investment results that correspond to the total return of stocks of non-U.S. large- and mid-capitalization companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0000 0 0.0000 0.0000 Based on estimated amounts for the current fiscal year. 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 the 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. This example does not include any fees paid at the fee-based account or plan level. 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: 0 0 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. Principal Investment Strategies Normally investing at least 80% of assets in securities of large- and mid-capitalization companies included in the Fidelity Global ex U.S. Focused IndexSM. The Fidelity Global ex U.S. Focused Index SM is designed to reflect the performance of stocks of non-U.S. large- and mid-capitalization companies. The Fidelity Global ex U.S. Focused Index SM was created by Fidelity Product Services LLC (FPS) using a rules-based proprietary index methodology that includes all non- U.S. large- and mid-capitalization stocks meeting certain market capitalization, liquidity and investability requirements. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Using statistical sampling techniques based on such factors as capitalization, industry exposures, dividend yield, price-to-earnings (P/E) ratio, price-to-book (P/B) ratio, earnings growth, country weightings, and the effect of foreign taxes to attempt to replicate the returns of the Fidelity Global ex U.S. Focused IndexSM. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Foreign and Emerging Markets Risk. Foreign markets, particularly emerging markets, can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market. The extent of economic development; political stability; market depth, infrastructure, and capitalization; and regulatory oversight can be less than in more developed markets. Emerging markets typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. Emerging markets can be subject to greater social, economic, regulatory, and political uncertainties and can be extremely volatile. Foreign exchange rates also can be extremely volatile. Geographic Exposure to Asia. Because the fund invests a meaningful portion of its assets in Asia, the fund's performance is expected to be closely tied to social, political, and economic conditions within Asia and to be more volatile than the performance of more geographically diversified funds. Geographic Exposure to Europe. Because the fund invests a meaningful portion of its assets in Europe, the fund's performance is expected to be closely tied to social, political, and economic conditions within Europe and to be more volatile than the performance of more geographically diversified funds. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. The fund will be concentrated to approximately the same extent that the fund's index concentrates in the securities of issuers in a particular industry or group of industries. Rules-Based Strategy Risk. Although the index uses a rules-based proprietary index methodology, there is no guarantee that this methodology will be successful.  Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance Performance history will be available for the fund after the fund has been in operation for one calendar year. Performance history will be available for the fund after the fund has been in operation for one calendar year. Fund Summary Fund: Fidelity Flex® Mid Cap Focused Index Fund Investment Objective Fidelity Flex® Mid Cap Focused Index Fund seeks to provide investment results that correspond to the total return of stocks of mid-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0000 0 0.0000 0.0000 Based on estimated amounts for the current fiscal year. 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 the 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. This example does not include any fees paid at the fee-based account or plan level. 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: 0 0 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. Principal Investment Strategies Normally investing at least 80% of assets in securities of mid-capitalization companies included in the Fidelity U.S. Mid Cap Focused IndexSM. The Fidelity U.S. Mid Cap Focused Index SM is designed to reflect the performance of stocks of mid-capitalization U.S. companies. Mid-capitalization stocks are considered to be stocks whose market capitalization is similar to the market capitalization of companies in the Russell Midcap ® Index or the S&P MidCap 400 ® Index. The Fidelity U.S. Mid Cap Focused Index SM was created by Fidelity Product Services LLC (FPS) using a rules-based proprietary index methodology that includes all U.S. stocks meeting certain market capitalization, liquidity and investability requirements. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Using statistical sampling techniques based on such factors as capitalization, industry exposures, dividend yield, price-to-earnings (P/E) ratio, price-to-book (P/B) ratio, and earnings growth to attempt to replicate the returns of the Fidelity U.S. Mid Cap Focused IndexSM. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. The fund will be concentrated to approximately the same extent that the fund's index concentrates in the securities of issuers in a particular industry or group of industries. Rules-Based Strategy Risk. Although the index uses a rules-based proprietary index methodology, there is no guarantee that this methodology will be successful.  Mid Cap Investing. The value of securities of medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance Performance history will be available for the fund after the fund has been in operation for one calendar year. Performance history will be available for the fund after the fund has been in operation for one calendar year. Fund Summary Fund: Fidelity Flex® Small Cap Focused Index Fund Investment Objective Fidelity Flex® Small Cap Focused Index Fund seeks to provide investment results that correspond to the total return of stocks of small-capitalization U.S. companies. Fee Table The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below. Shareholder fees 0 Annual Operating Expenses 0.0000 0 0.0000 0.0000 Based on estimated amounts for the current fiscal year. 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 the 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. This example does not include any fees paid at the fee-based account or plan level. 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: 0 0 Portfolio Turnover The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. Principal Investment Strategies Normally investing at least 80% of assets in securities of small-capitalization companies included in the Fidelity U.S. Small Cap Focused IndexSM. The Fidelity U.S. Small Cap Focused Index SM is designed to reflect the performance of stocks of small-capitalization companies. Small-capitalization stocks are considered to be stocks whose market capitalization is similar to the market capitalization of companies in the Russell 2000 ® Index or the S&P SmallCap 600 ® Index. The Fidelity U.S. Small Cap Focused Index SM was created by Fidelity Product Services LLC (FPS) using a rules-based proprietary index methodology that includes all U.S. stocks meeting certain market capitalization, liquidity and investability requirements. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Using statistical sampling techniques based on such factors as capitalization, industry exposures, dividend yield, price-to-earnings (P/E) ratio, price-to-book (P/B) ratio, and earnings growth to attempt to replicate the returns of the Fidelity U.S. Small Cap Focused IndexSM. Lending securities to earn income for the fund. Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments. Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty. Correlation to Index. The performance of the fund and its underlying index may vary somewhat due to factors such as fees and expenses of the fund, transaction costs, sample selection, regulatory restrictions, and timing differences associated with additions to and deletions from the index. Errors in the construction or calculation of the index may occur from time to time and may not be identified and corrected for some period of time, which may have an adverse impact on the fund and its shareholders. Passive Management Risk. The fund is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the fund's index or of the actual securities included in the index. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the fund's performance could be lower than actively managed funds that may shift their portfolio assets to take advantage of market opportunities or lessen the impact of a market decline or a decline in the value of one or more issuers. The fund will be concentrated to approximately the same extent that the fund's index concentrates in the securities of issuers in a particular industry or group of industries. Rules-Based Strategy Risk. Although the index uses a rules-based proprietary index methodology, there is no guarantee that this methodology will be successful.  Small Cap Investing. The value of securities of smaller, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers. Securities Lending Risk. Securities lending involves the risk that the borrower may fail to return the securities loaned in a timely manner or at all. If the borrower defaults on its obligation to return the securities loaned because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities loaned or in gaining access to the collateral. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .   You could lose money by investing in the fund. Performance Performance history will be available for the fund after the fund has been in operation for one calendar year. Performance history will be available for the fund after the fund has been in operation for one calendar year. A Based on estimated amounts for the current fiscal year. B The fund is available only to certain fee-based accounts and advisory programs offered by Fidelity. Advisory account clients, retirement plans, plan sponsors and/or plan participants typically pay an advisory fee that generally covers investment advisory and administrative services. A Based on estimated amounts for the current fiscal year. B The fund is available only to certain fee-based accounts and advisory programs offered by Fidelity. Advisory account clients, retirement plans, plan sponsors and/or plan participants typically pay an advisory fee that generally covers investment advisory and administrative services. A Based on estimated amounts for the current fiscal year. B The fund is available only to certain fee-based accounts and advisory programs offered by Fidelity. Advisory account clients, retirement plans, plan sponsors and/or plan participants typically pay an advisory fee that generally covers investment advisory and administrative services.