KKR Income Opportunities Fund : Fund Prospectus

PROSPECTUS

January 13, 2023

$100,000,000

KKR Income Opportunities Fund

Common Shares

Subscription Rights to Purchase Common Shares

Preferred Shares

Investment Objectives. KKR Income Opportunities Fund (the "Fund") is a diversified, closed-end management investment company. The Fund's primary investment objective is to seek a high level of current income with a secondary objective of capital appreciation. The Fund is not intended as, and you should not construe it to be, a complete investment program. There can be no assurance that the Fund will achieve its investment objectives or be able to structure its investment portfolio as anticipated.

Investment Strategies. The Fund seeks to achieve its investment objectives by employing a dynamic strategy of investing in a targeted portfolio of loans and fixed-income instruments of U.S. and non-U.S. issuers and implementing hedging strategies in order to seek to achieve attractive risk-adjusted returns. Under normal market conditions, the Fund invests at least 80% of its Managed Assets (as defined herein) in loans and fixed-income instruments or other instruments, including derivative instruments, with similar economic characteristics (the "80% Policy"). "Managed Assets" means the total assets of the Fund (including any assets attributable to borrowings for investment purposes) minus the sum of the Fund's accrued liabilities (other than liabilities representing borrowings for investment purposes). The Fund invests primarily in first- and second-lien secured loans, unsecured loans and high-yield corporate debt instruments of varying maturities. The instruments in which the Fund invests may be rated investment grade or below investment grade by a nationally recognized statistical rating organization, or unrated. The Fund's investments in below investment grade loans, below investment grade fixed-income instruments and debt instruments of financially troubled companies are considered speculative with respect to the issuer's capacity to pay interest and repay principal. These investments are commonly referred to as "high-yield" or "junk" instruments. The Fund seeks to tactically and dynamically allocate capital across companies' capital structures where KKR Credit Advisors (US) LLC (the "Adviser") believes its due diligence process has identified compelling investment opportunities, including where the Adviser has identified issuer distress, event-driven misvaluations of securities or capital market inefficiencies. See "Investment Objectives and Investment Strategies."

We may offer, from time to time, in one or more offerings, the Fund's common shares and/or preferred shares of beneficial interest, each with a par value of $0.001 per share, and/or subscription rights to purchase common shares, which we refer to collectively as the "securities." Securities may be offered at prices and on terms to be set forth in one or more supplements to this prospectus (each a "prospectus supplement"). You should read this prospectus and the applicable prospectus supplement carefully before you invest in our securities.

Our securities may be offered directly to one or more purchasers, including existing shareholders in a rights offering, through agents designated from time to time by us, to or through underwriters or dealers, "at-the-market" to or through a market maker into an existing trading market, or through a combination of methods of sale. The prospectus supplement relating to any sale of preferred shares will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period, and other matters. The prospectus supplement relating to the offering will identify any agents or underwriters involved in the sale of our securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between us and our agents or underwriters, or among our underwriters, or the basis upon which such amount may be calculated. The prospectus supplement relating to any offering of subscription rights will set forth the number of shares issuable upon the exercise of each right (or number of rights) and the other terms of such rights offering. We may not sell any of our securities through agents, underwriters or dealers without delivery of a prospectus supplement describing the method and terms of the particular offering.

The Fund's common shares are listed on the New York Stock Exchange (the "NYSE") under the trading or "ticker" symbol "KIO." On January 4, 2023 the last reported sale price of the Fund's common shares was $11.11. The net asset value of the Fund's common shares at the close of business on January 4, 2023 was $12.39 per share. Shares of closed-end funds often trade at a discount from net asset value. This creates a risk of loss for an investor purchasing shares in a public offering.

Investing in the Fund's shares involves certain risks. See "Risk Factors" of this prospectus for factors that should be considered before investing in shares of the Fund.

Neither the Securities and Exchange Commission (the "SEC") nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus may not be used to consummate sales of shares by us through agents, underwriters or dealers unless accompanied by a prospectus supplement.

This prospectus, together with the applicable prospectus supplement, sets forth concisely information about the Fund you should know before investing. Please read this prospectus carefully before deciding whether to invest and retain it for future reference. A Statement of Additional Information (the "SAI") dated January 13, 2023, has been filed with the SEC. This prospectus incorporates by reference the entire SAI. The SAI is available along with other Fund-related materials are available on the EDGAR database on the SEC's Internet site (http://www.sec.gov), and copies of this information may be obtained, after paying a duplicating fee, by electronic request at [e-mail].

You may also request a free copy of the SAI, annual and semi-annual reports to shareholders, and additional information about the Fund, and may make other shareholder inquiries, by calling [phone], by writing to the Fund or visiting the Fund's website (https://www.kkrfunds.com/kio/). The information contained in, or accessed through, the Fund's website is not part of this prospectus.

The Fund's shares do not represent a deposit or obligation of, and are not guaranteed by or endorsed by, any bank or other insured depositary institution, and are not federally insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

TABLE OF CONTENTS

PROSPECTUS SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY OF COMMON SHAREHOLDER FEES AND EXPENSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 FINANCIAL HIGHLIGHTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 SENIOR SECURITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 THE FUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 USE OF PROCEEDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 INVESTMENT OBJECTIVES AND INVESTMENT STRATEGIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 LEVERAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 RISK FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 CONFLICTS OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 MANAGEMENT OF THE FUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 CALCULATION OF NET ASSET VALUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 DISTRIBUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 DIVIDEND REINVESTMENT PLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 DESCRIPTION OF THE SECURITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 TAX CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 CLOSED-END FUND STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 RIGHTS OFFERINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 DESCRIPTION OF CAPITAL STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 CUSTODIAN, DIVIDEND PAYING AGENT, TRANSFER AGENT AND REGISTRAR . . . . . . . . . . . . . . 58 PLAN OF DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 LEGAL MATTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 ADDITIONAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 INCORPORATION BY REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

You should rely only on the information contained in or incorporated by reference into this prospectus and the applicable prospectus supplement. Neither the Fund nor the underwriters have authorized anyone to provide you with different information. The Fund is not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should not assume that the information contained in this prospectus and the applicable prospectus supplement is accurate as of any date other than the date of this prospectus and the applicable prospectus supplement. The Fund's business, financial condition, results of operations and prospects may have changed since that date.

FORWARD-LOOKING STATEMENTS

This prospectus contains or incorporates by reference forward-looking statements. These statements describe the Fund's plans, strategies, and goals and our beliefs and assumptions concerning future economic and other conditions and the outlook for the Fund, based on currently available information. Forward-looking statements can be identified by the words "may," "will," "intend," "expect," "estimate," "continue," "plan," "anticipate," and similar terms and the negative of such terms are used in an effort to identify forward-looking statements, although some forward-looking statements may be expressed differently. By their nature, all forward-looking statements involve risks and uncertainties, and actual results could differ materially from those contemplated by the forward-looking statements. Several factors that could materially affect our actual results are the performance of the portfolio of securities we hold, the price at which our shares will trade in the public markets and other factors discussed in our periodic filings with the SEC. The forward-looking statements contained in or incorporated by reference into this Prospectus are excluded from the safe harbor protection provided by Section 27A of the Securities Act.

PROSPECTUS SUMMARY

This is only a summary. This summary does not contain all of the information that you should consider before investing in the Fund's securities. You should review the more detailed information contained in this prospectus and in the Statement of Additional Information (the "SAI").

The Fund

KKR Income Opportunities Fund is a diversified, closed-end management investment company organized as a statutory trust under the laws of the State of Delaware on March 17, 2011. Throughout this prospectus, we refer to KKR Income Opportunities Fund as the "Fund" or as "we."

The Fund's outstanding common shares of beneficial interest, par value of $0.001 per share, are listed on the New York Stock Exchange ("NYSE") under the trading or "ticker" symbol "KIO," and any newly issued common shares issued will trade under the same symbol. As of January 4, 2023, the Fund had outstanding 20,340,315 common shares. On January 4, 2023, the last reported sale price of the Fund's common shares on the NYSE was $11.11 per share. The net asset value ("NAV") of the Fund's common shares at the close of business on January 4, 2023 was $12.39 per share.

The Offering

We may offer, from time to time, in one or more offerings, our common shares and/or preferred shares, $0.001 par value per share, or our subscription rights to purchase our common shares, which we refer to collectively as the "securities." We may issue either transferable or non-transferable subscription rights. The preferred shares are expected to be fixed rate preferred shares. In connection with a rights offering, we may sell our common shares at a price below the NAV per share and, if the subscription price in any such offering is less than the NAV per share of our common shares, then you may experience an immediate dilution of the aggregate NAV of your shares. The securities may be offered at prices and on terms to be set forth in one or more supplements to this prospectus (each a "prospectus supplement"). You should read this prospectus and the applicable prospectus supplement carefully before you invest in our securities. Our securities may be offered directly to one or more purchasers, through agents designated from time to time by us, to or through underwriters or dealers, "at-the-market" to or through a market maker into an existing trading market, or through a combination of methods of sale. The prospectus supplement relating to the offering will identify any agents, underwriters or dealers involved in the sale of our securities, and will set forth any applicable purchase price, fee, commission or discount arrangement between us and our agents or underwriters, or among our underwriters, or the basis upon which such amount may be calculated. The prospectus supplement relating to any sale of preferred shares will set forth the liquidation preference and information about the dividend period, dividend rate, any call protection or non-call period and other matters. The prospectus supplement relating to any offering of subscription rights will set forth the number of shares issuable upon the exercise of each right (or number of rights) and the other terms of such rights offering. We may not sell any of our securities through agents, underwriters or dealers without delivery of a prospectus supplement describing the method and terms of the particular offering.

Investment Objectives

Please refer to the section of the Fund's most recent annual report on Form N-CSR entitled "Investment Objectives," which is incorporated by reference herein, for a discussion of the Fund's investment objectives.

Investment Strategies

Please refer to the section of the Fund's most recent annual report on Form N-CSR entitled "Investment Strategies," which is incorporated by reference herein, for a discussion of the Fund's investment strategies.

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Temporary Investments

During temporary defensive periods, including during the period when the proceeds of the offering of common shares are being invested, the Fund may deviate from its investment objectives and investment strategies. During such periods, the Fund may invest all or a portion of its assets in certain short-term (less than one year to maturity) and medium-term (not greater than five years to maturity) debt securities or hold cash and cash equivalents. The short- and medium-term debt securities in which the Fund may invest include (i) obligations of the U.S. government, its agencies or instrumentalities; (ii) bank deposits and bank obligations (including certificates of deposit, time deposits and bankers' acceptances) of U.S. or foreign banks denominated in any currency; (iii) floating rate securities and other instruments denominated in any currency issued by various governments or international development agencies; (iv) finance company and corporate commercial paper and other short-term corporate debt obligations of U.S. or foreign corporations; (v) repurchase agreements with banks and broker- dealers with respect to such securities; and (vi) shares of money market funds and money market instruments. See "Investment Objectives and Investment Strategies-PortfolioComposition-Temporary Investments" and "Use of Proceeds" below.

Leverage

The Fund is permitted to obtain leverage using any form or combination of financial leverage instruments, including through funds borrowed from banks or other financial institutions (i.e., a credit facility), margin facilities, the issuance of preferred shares or notes and leverage attributable to reverse repurchase agreements, dollar rolls or similar transactions. The Fund currently employs leverage through a credit facility and outstanding Series A Mandatory Redeemable Preferred Shares ("MRPS"). As of December 31, 2022, the Fund had approximately $99,431,119 in outstanding borrowings under the credit facility and 2,000,000 MRPS outstanding with a total liquidation value of $50,000,000. See "Preferred Shares." In the future, the Fund may use forms of leverage other than and/or in addition to a credit facility and preferred shares. The Fund may use leverage opportunistically and may choose to increase or decrease its leverage, or use different types or combinations of leveraging instruments, at any time based on the Fund's assessment of market conditions and the investment environment. There can be no assurance that the Fund will use leverage or that its leveraging strategy will be successful during any period in which it is employed. See "Risk Factors."

Common Shares

The Fund is authorized to issue an unlimited number of shares of beneficial interest, par value $0.001 per share, in multiple classes and series thereof as determined from time to time by the Board. The Board has authorized issuance of an unlimited number of common shares. Each share has equal voting, dividend, distribution and liquidation rights. The common shares are not redeemable and have no preemptive, conversion or cumulative voting rights. In the event of liquidation, each common share is entitled to its proportion of the Fund's assets after payment of debts and expenses. As of January 4, 2023, 20,340,315 common shares of the Fund were outstanding.

Preferred Shares

On October 15, 2019, the Fund issued 2,000,000 MRPS with a total liquidation value of $50,000,000. The final redemption date of the MRPS is October 31, 2029. The Fund makes quarterly dividend payments on the MRPS at an annual dividend rate of 3.81%.

The Fund is authorized to issue an unlimited number of shares that have been classified by the Board as preferred shares, par value $0.001 per share. The terms of each series of preferred shares may be fixed by the Board and may materially limit and/or qualify the rights of holders of the Fund's common shares. If the Board determines

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that it may be advantageous to the holders of the Fund's common shares for the Fund to utilize additional leverage, the Fund may issue additional series of fixed rate preferred shares ("Fixed Rate Preferred Shares"). Any Fixed Rate Preferred Shares issued by the Fund will pay distributions at a fixed rate, which may be reset after an initial period. Any borrowings may be at fixed or floating rates. Leverage creates a greater risk of loss as well as a potential for more gains for the common shares than if leverage were not used. See "Risk Factors." The Fund may borrow money to the extent permitted by applicable law in accordance with its investment restrictions.

Investment Advisory Agreement

Pursuant to an investment advisory agreement, the Adviser will receive an annual fee, payable monthly by the Fund, in an amount equal to 1.10% of the Fund's average daily Managed Assets (the "Management Fee").

During periods when the Fund is using leverage, the Management Fee paid to the Adviser will be higher than if the Fund did not use leverage because the Management Fee paid is calculated on the basis of the Fund's Managed Assets, which includes the assets purchased through leverage. See "Risk Factors."

The Administrator

U.S. Bancorp Fund Services, LLC (the "Administrator"), located at 615 East Michigan Street, Milwaukee, Wisconsin 53202, serves as administrator to the Fund. Under the administration agreement, the Administrator is responsible for calculating the NAV of the common shares and generally managing the administrative affairs of the Fund.

The Administrator is entitled to receive a monthly fee based on the average daily value of the Fund's net assets, subject to a minimum annual fee, plus out-of-pocket expenses. See "Management of the Fund-The Administrator."

Distributions

The Fund currently makes regular monthly cash distributions of all or a portion of its net investment income to shareholders of common shares ("Common Shareholders"). The Fund distributes to Common Shareholders at least annually all or substantially all of its net investment income after the payment of interest, fees and dividends, if any, owed with respect to any outstanding forms of leverage utilized by the Fund. The Fund intends to pay any capital gains distributions at least annually. If the Fund realizes a long-term capital gain, it will be required to allocate such gain between the common shares and any preferred shares issued by the Fund in proportion to the total distributions paid to each class for the year in which the income is realized. See "Distributions."

Various factors affect the level of the Fund's income, including the asset mix, the average maturity of the Fund's portfolio, the amount of leverage utilized by the Fund and the Fund's use of hedging. To permit the Fund to maintain a more stable monthly distribution, the Fund may, from time to time, distribute less than the entire amount of income earned in a particular period. The undistributed income would be available to supplement future distributions. As a result, the distributions paid by the Fund for any particular monthly period may be more or less than the amount of income actually earned by the Fund during that period. Undistributed income will add to the Fund's NAV (and indirectly benefit the Adviser and the Administrator by increasing their fees) and, correspondingly, distributions from the Fund's income will reduce the Fund's NAV. See "Distributions."

In accordance with the Fund's Amended and Restated Declaration of Trust (the "Declaration of Trust") and as required by the 1940 Act, all preferred shares of the Fund, including the MRPS, must have the same seniority with respect to distributions. Accordingly, no full distribution will be declared or paid on any series of preferred

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