Filed Pursuant to Rule 497(d)

Registration File No.: 333-214530

BLACKROCK FLOATING RATE INCOME STRATEGIES FUND, INC.

Supplement dated August 23, 2018 to the

Prospectus, dated December 20, 2017 of

BlackRock Floating Rate Income Strategies Fund, Inc.

This supplement amends certain information in the Prospectus (the “Prospectus”), dated December 20, 2017, of BlackRock Floating Rate Income Strategies Fund, Inc. (the “Fund”). Unless otherwise indicated, all other information included in the Prospectus that is not inconsistent with the information set forth in this supplement remains unchanged. Capitalized terms not otherwise defined in this supplement have the same meaning as in the Prospectus.

Any reference to BlackRock’s website in this supplement is intended to allow public access to information regarding the Fund and does not, and is not intended to, incorporate BlackRock’s website into this supplement or the Prospectus.

On June 13, 2018, the Investment Advisor announced changes to the Fund’s portfolio managers, effective August 31, 2018. The Fund’s portfolio managers as of August 31, 2018 are David Delbos, Mitchell S. Garfin, Joshua Tarnow, Carly Wilson and Abigail Apistolas.

Item 9 of Part I of the Prospectus entitled “Management” and Item 21 of Part I and II of the Prospectus entitled “Portfolio Manager” are deleted in their entirety and replaced with the following:

Item 9. Management

1.

BlackRock Advisors, LLC acts as the investment adviser for the Fund. Pursuant to an investment management agreement between the Investment Advisor and the Fund (the “Investment Management Agreement”), the Fund pays the Investment Advisor a monthly fee at an annual rate of 0.75% of the Fund’s average daily Managed Assets (1.05% of the Fund’s net assets, assuming leverage of approximately 30% of the Fund’s Managed Assets). Because the management fee is calculated on the basis of Managed Assets, which includes assets attributable to leverage, the fee paid to the Investment Advisor will be higher than if the Fund did not use leverage.

A discussion regarding the basis for the approval of the Investment Management Agreement by the Board is available in the Fund’s Annual Report to shareholders for the fiscal year ended August 31, 2017.

The Fund is managed by a team of investment professionals comprised of David Delbos, Managing Director of BlackRock; Mitchell S. Garfin, CFA, Managing Director of BlackRock; Joshua Tarnow, Managing Director of BlackRock; Carly Wilson, Director of BlackRock; and Abigail Apistolas, CFA, Associate of BlackRock. Each is jointly responsible for the day-to-day management of the registrant’s portfolio, which includes setting the registrant’s overall investment strategy, overseeing the management of the registrant and/or selection of its investments.

Additional information regarding the Board, the Investment Advisor and the portfolio managers, including the portfolio managers’ compensation, other accounts managed and ownership of Fund securities, is included under Item 21, below, and under Item 9, Item 18 and Item 21 in Part II.

State Street Bank and Trust Company provides certain administration and accounting services to the Fund pursuant to an Administrative Services Agreement (the “Administration Agreement”). State Street Bank and Trust Company is paid a monthly fee at an annual rate ranging from 0.0075% to 0.015% of the Fund’s Managed Assets, along with an annual fixed fee ranging from $3,000 to $10,000 for the services it provides to the Fund.

Certain legal matters will be passed upon by Miles & Stockbridge P.C., which serves as special Maryland counsel to the Fund.

See “Other Service Providers” under Item 9 in Part II for additional information about State Street Bank and Trust Company, the Fund’s other service providers and other matters relevant to the Fund’s management.

2.	Not applicable.

3.	Not applicable.

1.	The following table sets forth information about funds and accounts other than the Fund for which the portfolio managers are primarily responsible for the day-to-day portfolio management as of May 31, 2018:

Conflicts of Interest:  Mses. Apistolas and Wilson and Messrs. Delbos, Garfin and Tarnow may be managing certain hedge fund and/or long only accounts, or may be part of a team managing certain hedge fund and/or long only accounts, subject to incentive fees. Mses. Apistolas and Wilson and Messrs. Delbos, Garfin and Tarnow may therefore be entitled to receive a portion of any incentive fees earned on such accounts.  See “Portfolio Managers — Potential Material Conflicts of Interest” under Item 21 in Part II.

2.

See Item 21 in Part II for a general overview and description of the structure of, and the method used to determine, the compensation of the portfolio managers. The principal components of compensation include a base salary, a performance-based discretionary bonus, participation in various benefits programs and one or more of the incentive compensation programs established by BlackRock. The following sets forth how various components of this compensation structure apply specifically to these portfolio managers as of May 31, 2018.

Deferred Compensation Program.  Deferred BlackRock, Inc. stock awards are generally granted in the form of BlackRock, Inc. restricted stock units that vest pursuant to the terms of the applicable plan and, once vested, settle in BlackRock, Inc. common stock.  The portfolio managers of this Fund have deferred BlackRock, Inc. stock awards.

Discretionary Incentive Compensation.  Only portfolio managers who manage specified products and whose total compensation is above a specified threshold are eligible to participate in the deferred cash award program.

Incentive Savings Plan.  All of the eligible portfolio managers are eligible to participate in these plans.

3.	As of May 31, 2018, the portfolio managers beneficially owns the following dollar ranges of equity securities in the Fund:

 

Portfolio Manager		Dollar Range of Equity Securities of the Fund Beneficially Owned
David Delbos		$100,001-$500,000
Mitchell S. Garfin, CFA		None
Joshua Tarnow		$100,001-$500,000
Carly Wilson		None
Abigail Apistolas, CFA		None

BlackRock has built a professional working environment, firm-wide compliance culture and compliance procedures and systems designed to protect against potential incentives that may favor one account over another. BlackRock has adopted policies and procedures that address the allocation of investment opportunities, execution of portfolio transactions, personal trading by employees and other potential conflicts of interest that are designed to ensure that all client accounts are treated equitably over time. Nevertheless, BlackRock furnishes investment management and advisory services to numerous clients in addition to the Fund, and BlackRock may, consistent with applicable law, make investment recommendations to other clients or accounts (including accounts which are hedge funds or have performance or higher fees paid to BlackRock, or in which portfolio managers have a personal interest in the receipt of such fees), which may be the same as or different from those made to the Fund. In addition, BlackRock, Inc., its affiliates and significant shareholders and any officer, director, shareholder or employee may or may not have an interest in the securities whose purchase and sale BlackRock recommends to the Fund. BlackRock, Inc., or any of its affiliates or significant shareholders, or any officer, director, shareholder, employee or any member of their families may take different actions than those recommended to the Fund by BlackRock with respect to the same securities. Moreover, BlackRock may refrain from rendering any advice or services concerning securities of companies of which any of BlackRock, Inc.’s (or its affiliates’ or significant shareholders’) officers, directors or employees are directors or officers, or companies as to which BlackRock, Inc. or any of its affiliates or significant shareholders or the officers, directors and employees of any of them has any substantial economic interest or possesses material non-public information. Certain portfolio managers also may manage accounts whose investment strategies may at times be opposed to the strategy utilized for the Fund.

As a fiduciary, BlackRock owes a duty of loyalty to its clients and must treat each client fairly. When BlackRock purchases or sells securities for more than one account, the trades must be allocated in a manner consistent with its fiduciary duties. BlackRock attempts to allocate investments in a fair and equitable manner among client accounts, with no account receiving preferential treatment. To this end, BlackRock, Inc. has adopted policies that are intended to ensure reasonable efficiency in client transactions and provide BlackRock with sufficient flexibility to allocate investments in a manner that is consistent with the particular investment discipline and client base, as appropriate.

BlackRock’s financial arrangements with its portfolio managers, its competitive compensation and its career path emphasis at all levels reflect the value senior management places on key resources. Compensation may include a variety of components and may vary from year to year based on a number of factors. The principal components of compensation include a base salary, a performance-based discretionary bonus, participation in various benefits programs and one or more of the incentive compensation programs established by BlackRock.  The following information is as of May 31, 2018.

Base Compensation.  Generally, portfolio managers receive base compensation based on their position with the firm.

Discretionary Incentive Compensation.  See Item 21 in Part I.

Distribution of Discretionary Incentive Compensation.  Discretionary incentive compensation is distributed to portfolio managers in a combination of cash, deferred BlackRock, Inc. stock awards, and/or deferred cash awards that notionally track the return of certain BlackRock investment products.

Portfolio managers receive their annual discretionary incentive compensation in the form of cash. Portfolio managers whose total compensation is above a specified threshold also receive deferred BlackRock, Inc. stock awards annually as part of their discretionary incentive compensation. Paying a portion of discretionary incentive compensation in the form of deferred BlackRock, Inc. stock puts compensation earned by a portfolio manager for a given year “at risk” based on BlackRock’s ability to sustain and improve its performance over future periods.  In some cases, additional deferred BlackRock, Inc. stock may be granted to certain key employees as part of a long-term incentive award to aid in retention, align interests with long-term shareholders and motivate performance.  Deferred BlackRock, Inc. stock awards are generally granted in the form of BlackRock, Inc. restricted stock units that vest pursuant to the terms of the applicable plan and, once vested, settle in BlackRock, Inc. common stock.

For certain portfolio managers, a portion of the discretionary incentive compensation is also distributed in the form of deferred cash awards that notionally track the returns of select BlackRock investment products they manage, which provides direct alignment of portfolio manager discretionary incentive compensation with investment product results. Deferred cash awards vest ratably over a number of years and, once vested, settle in the form of cash.  Only portfolio managers who manage specified products and whose total compensation is above a specified threshold are eligible to participate in the deferred cash award program.

Other Compensation Benefits.  In addition to base compensation and discretionary incentive compensation, portfolio managers may be eligible to receive or participate in one or more of the following:

Incentive Savings Plans — BlackRock, Inc. has created a variety of incentive savings plans in which BlackRock, Inc. employees are eligible to participate, including a 401(k) plan, the BlackRock Retirement Savings Plan (RSP), and the BlackRock Employee Stock Purchase Plan (ESPP). The employer contribution components of the RSP include a company match equal to 50% of the first 8% of eligible pay contributed to the plan capped at $5,000 per year, and a company retirement contribution equal to 3-5% of eligible compensation up to the Internal Revenue Service limit ($275,000 for 2018). The RSP offers a range of investment options, including registered investment companies and collective investment funds managed by the firm. BlackRock, Inc. contributions follow the investment direction set by participants for their own contributions or, absent participant investment direction, are invested into a target date fund that corresponds to, or is closest to, the year in which the participant attains age 65. The ESPP allows for investment in BlackRock, Inc. common stock at a 5% discount on the fair market value of the stock on the purchase date. Annual participation in the ESPP is limited to the purchase of 1,000 shares of common stock or a dollar value of $25,000 based on its fair market value on the purchase date. All of the eligible portfolio managers are eligible to participate in these plans.

See Item 9 and Item 21 in Part I for additional information about the Fund’s portfolio managers.

Shareholders should retain this supplement for future reference