Summary Prospectus by Investment Company (Form 497K)

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation and current income.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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 fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 94.22% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Fund will generally seek exposure to a number of different asset classes based on an asset allocation framework developed by the Investment Policy Committee of The Northern Trust Company ("TNTC") and NTI (TNTC and NTI are collectively referred to herein as "Northern Trust"). The asset classes in which the Fund seeks to obtain exposure include but are not limited to small-, mid- and large-capitalization common stocks; real estate securities; commodity-related securities; mortgage- and asset-backed securities; and fixed-income securities, including high yield securities and money market instruments. The Fund primarily obtains exposure to these asset classes by investing in shares of underlying mutual funds and exchange-traded funds ("ETFs"), including mutual funds and ETFs for which NTI, the Fund's investment adviser, or an affiliate acts as investment adviser (collectively, "Underlying Funds"). The Fund also may obtain exposure to one or more asset classes by investing directly in equity or fixed-income securities or money market instruments. In addition, the Fund also may invest directly in derivatives, including but not limited to forward

foreign currency exchange contracts, futures contracts and options on futures contracts, for hedging purposes.

The Fund may obtain exposure to securities of U.S. and foreign issuers, including those in emerging markets countries (i.e., those that are generally in the early stages of their industrial cycles). The Fund expects its foreign exposure to be allocated among various regions or countries, including the United States (but in no less than three different countries).

Northern Trust's Investment Policy Committee is responsible for developing tactical asset allocation recommendations with respect to the Fund using the asset allocation framework and incorporating various criteria, including, for example, economic factors such as gross domestic product and inflation; fixed-income market factors such as sovereign yields, credit spreads and currency trends; and equity market factors such as domestic and foreign operating earnings and valuation levels. NTI monitors the Fund daily to ensure it is invested pursuant to the current asset allocation framework. NTI reviews the asset allocation framework and recommended allocations at least monthly, or more frequently as needed, to consider adjusting the allocations based on its evolving investment views amid changing market and economic conditions. There is no limit in the number of Underlying Funds in which the Fund may invest. The Fund is not required to maintain any minimum or maximum investment in any asset class.

From time to time the Fund may have a focused investment (i.e., investment exposure comprising more than 15% of its total assets) in one or more particular sectors. As of March 31, 2025, the Fund had a focused investment in the financials and information technology sectors.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund's performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund's net asset value ("NAV"), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

Because the Fund invests primarily in the Underlying Funds, the risks described below are in reference to the Underlying Funds, and to the extent that the Fund invests directly in securities and other instruments, the risks described below are also directly applicable to the Fund.

MARKET RISK is the risk that the value of the Fund's investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments. During periods of market disruption or other abnormal market conditions, the Fund's exposure to risks described elsewhere in this summary will likely increase.

ASSET ALLOCATION RISK is the risk that the selection by a manager of the Underlying Funds and the allocation of the Fund's assets among the various asset classes and market segments will not perform as expected. The Fund's investment in any one Underlying Fund or asset class may exceed 15% of the Fund's total assets, which may cause it to be subject to greater volatility and risk than a more diversified fund.

UNDERLYING FUND RISK is the risk that the Fund's investment performance and its ability to achieve its investment objective are directly related to the performance of the Underlying Funds in which it invests. There can be no assurance that the Underlying Funds will achieve their respective investment objectives. The Fund will be subject to the risks associated with investments in the Underlying Funds, such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. In addition, passively managed Underlying Funds may not track the performance of their respective reference assets and may hold troubled securities or other investments. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Fund indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. Further, investments in ETFs are subject to the following additional risks: (1) an ETF's shares may trade above or below its net asset value; (2) an active trading market for the ETF's shares may not develop or be maintained; and (3) trading an ETF's shares may be halted by the listing exchange. The Fund is subject to the risks of the Underlying Funds in direct proportion to the allocation of its assets among the Underlying Funds. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.

FOREIGN SECURITIES RISK is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets, and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments may impose limitations on foreigners' ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund's investments to decline. Foreign banks, agents and securities depositories that hold the Fund's foreign assets may be subject to little or no regulatory oversight over, or

independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

EMERGING MARKETS RISK is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund's ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company's assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., "growth", "value" or "quantitative") tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund's investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

COMMODITY-RELATED SECURITIES RISK is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in other kinds of securities. In addition to overall market movements, commodity-related securities may be adversely impacted by commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as weather, disease (including pandemics or epidemics), tariffs, embargoes or other trade barriers, acts of war or terrorism, or political and regulatory developments.

CREDIT (OR DEFAULT) RISK is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Fund's investments and its returns. Changes in an issuer's financial strength, the market's perception of an issuer's creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Fund's investment in that issuer.

DEBT EXTENSION RISK is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Fund later than expected. This will cause the value of the security, and the Fund's NAV, to decrease, and the Fund may lose opportunities to invest in higher yielding securities.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

GEOGRAPHIC RISK is the risk that if the Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund's investments more, and the Fund's investments may be more volatile, than if the Fund's investments were not so concentrated in such country or region.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

HIGH-YIELD RISK is the risk that the Fund's below-investment grade fixed-income securities, sometimes known as "junk bonds," will be subject to greater credit risk, price volatility, liquidity risk, and risk of loss than investment grade securities, which can adversely impact the Fund's return and NAV. High yield securities are considered highly speculative and are subject to the increased risk of an issuer's inability to make principal and interest payments.

INTEREST RATE RISK is the risk that during periods of rising interest rates, the market value of a Fund's securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of a Fund's securities will tend to be higher. A Fund's yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund. During periods when inflation rates are high or rising, or during periods of low interest rates, the Fund may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Fund's investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance.

SMALL AND MID CAP STOCK RISK is the risk that stocks of small and mid-sized companies may be more volatile than stocks of larger, more established companies. Small and mid-sized companies may have limited product lines or financial resources, may be dependent upon a particular niche of the market, or may be dependent upon a small or inexperienced management group. The securities of small and mid-sized companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally, the smaller the company size, the greater the risk.

ASSET-BACKED AND MORTGAGE-BACKED SECURITIES RISK is the risk that such securities may be less liquid than other bonds, and may be more sensitive than other bonds to the market's perception of issuers and creditworthiness of payees, particularly in declining general economic conditions when concern regarding mortgagees' ability to pay (e.g., the ability of homeowners, commercial mortgagees, consumers with student loans, automobile loans or credit card debtholders to make payments on the underlying loan pools) rises, which may result in the Fund experiencing difficulty selling or valuing these securities. In addition, these securities may not be backed by the full faith and credit of the U.S. government, have experienced extraordinary weakness and volatility at various times in recent years, and may decline quickly in the event of a substantial economic or market downturn. Those asset-backed and mortgage-backed securities that are guaranteed as to the timely payment of interest and principal by a government entity, are not guaranteed as to market price, which will fluctuate. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain asset-backed and mortgage-backed securities.

An unexpectedly high rate of defaults on the mortgages held by a mortgage pool may adversely affect the value of mortgage-backed securities and could result in losses to the Fund.

PREPAYMENT (OR CALL) RISK is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Fund earlier than expected. Issuers may be more likely to prepay when interest rates fall, when credit spreads change, or when an issuer's credit quality improves. If this happens, the Fund will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Fund's returns. The Fund may also lose any premium it paid to purchase the securities.

REAL ESTATE SECURITIES RISK is the risk that investments in real estate investment trusts ("REITs") and securities of real estate companies will make the Fund more susceptible to risks

associated with the ownership of real estate and with the real estate industry in general. These risks include possible declines in the value of real estate, possible lack of mortgage funds and unexpected vacancies of properties, defaults by borrowers or tenants, increases in property taxes, fluctuations in interest rates and limited availability of mortgage financing. REITs that invest in real estate mortgages are also subject to prepayment risks. REITs and real estate companies may be less diversified than other pools of securities, may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets. The Fund will indirectly bear its proportionate share of expenses, including management fees, paid by each REIT in which it invests, in addition to the expenses of the Fund.

U.S. GOVERNMENT SECURITIES RISK is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Fund are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future.

PORTFOLIO TURNOVER RISK is the risk that high portfolio turnover, including investments made on a shorter-term basis or instruments with a maturity of one year or less at the time of acquisition, may lead to increased Fund expenses that may result in lower investment returns. High portfolio turnover may also result in higher short-term capital gains taxable to shareholders.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of two broad-based securities market indices and a custom blended benchmark that reflects the investment instruments in which the Fund invests, in that order.

The Fund's past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Trust's website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2025 was 7.11%. For the periods shown in the bar chart above, the highest quarterly return was 12.55% in the second quarter of 2020, and the lowest quarterly return was (16.81)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2024)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns after taxes on distributions and sale of fund shares to be greater than the Returns after taxes on distributions or even the Returns before taxes.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Global Tactical Asset Allocation Fund. Anwiti Bahuguna, PhD, Executive Vice President of NTI, Colin Cheesman, Vice President of NTI, and Peter Wilke, Senior Vice President of NTI, have been managers of the Fund since December 2023, January 2025, and January 2025, respectively.

The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the "Trust") with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund's distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.