UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number: 811-23564

Name of Fund: BlackRock Capital Allocation Trust (BCAT)

Fund Address:    100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, BlackRock Capital Allocation Trust,

55 East 52^nd Street, New York, NY 10055

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 12/31/2022

Date of reporting period: 06/30/2022

Item 1 – Report to Stockholders

(a) The Report to Shareholders is attached herewith.

BlackRock Capital Allocation Trust (BCAT)

BlackRock ESG Capital Allocation Trust (ECAT)

Supplemental Information  (unaudited)

Section 19(a) Notices

BlackRock Capital Allocation Trust’s (BCAT) and BlackRock ESG Capital Allocation Trust’s (ECAT) (collectively, the “Trusts” or individually, a “Trust”) amounts and sources of distributions reported are estimates and are being provided to you pursuant to regulatory requirements and are not being provided for tax reporting purposes. The actual amounts and sources for tax reporting purposes will depend upon each Trust’s investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. Each Trust will provide a Form 1099-DIV each calendar year that will tell you how to report these distributions for U.S. federal income tax purposes.

June 30, 2022

Section 19(a) notices for the Trusts, as applicable, are available on the BlackRock website at blackrock.com.

Section 19(b) Disclosure

The Trusts, acting pursuant to a U.S. Securities and Exchange Commission (“SEC”) exemptive order and with the approval of each Trust’s Board of Trustees (the “Board”), each have adopted a managed distribution plan, consistent with its investment objectives and policies to support a level distribution of income, capital gains and/or return of capital (the “Plan”). In accordance with the Plans, the Trusts currently distribute the following fixed amounts per share on a monthly basis:

The fixed amounts distributed per share are subject to change at the discretion of each Trust’s Board. Under its Plan, each Trust will distribute all available net income to its shareholders as required by the Internal Revenue Code of 1986, as amended (the “Code”). If sufficient income (inclusive of net income and short-term capital gains) is not earned on a monthly basis, the Trusts will distribute long-term capital gains and/or return of capital to shareholders in order to maintain a level distribution. Each monthly distribution to shareholders is expected to be at the fixed amount established by the Board; however, each Trust may make additional distributions from time to time, including additional capital gain distributions at the end of the taxable year, if required to meet requirements imposed by the Code and/or the Investment Company Act of 1940, as amended (the “1940 Act”).

Shareholders should not draw any conclusions about each Trust’s investment performance from the amount of these distributions or from the terms of the Plan. Each Trust’s total return performance is presented in its financial highlights table.

The Board may amend, suspend or terminate a Trust’s Plan at any time without prior notice to the Trust’s shareholders if it deems such actions to be in the best interests of the Trust or its shareholders. The suspension or termination of the Plan could have the effect of creating a trading discount (if the Trust’s stock is trading at or above net asset value) or widening an existing trading discount. The Trusts are subject to risks that could have an adverse impact on their ability to maintain level distributions. Examples of potential risks include, but are not limited to, economic downturns impacting the markets, changes in interest rates, decreased market volatility, companies suspending or decreasing corporate dividend distributions and changes in the Code.

Table of Contents

The Benefits and Risks of Leveraging

The Trusts may utilize leverage to seek to enhance the distribution rate on, and net asset value (“NAV”) of, their common shares (“Common Shares”). However, there is no guarantee that these objectives can be achieved in all interest rate environments.

In general, the concept of leveraging is based on the premise that the financing cost of leverage, which is based on short-term interest rates, is normally lower than the income earned by a Trust on its longer-term portfolio investments purchased with the proceeds from leverage. To the extent that the total assets of each Trust (including the assets obtained from leverage) are invested in higher-yielding portfolio investments, each Trust’s shareholders benefit from the incremental net income. The interest earned on securities purchased with the proceeds from leverage (after paying the leverage costs) is paid to shareholders in the form of dividends, and the value of these portfolio holdings (less the leverage liability) is reflected in the per share NAV.

To illustrate these concepts, assume a Trust’s capitalization is $100 million and it utilizes leverage for an additional $30 million, creating a total value of $130 million available for investment in longer-term income securities. If prevailing short-term interest rates are 3% and longer-term interest rates are 6%, the yield curve has a strongly positive slope. In this case, a Trust’s financing costs on the $30 million of proceeds obtained from leverage are based on the lower short-term interest rates. At the same time, the securities purchased by a Trust with the proceeds from leverage earn income based on longer-term interest rates. In this case, a Trust’s financing cost of leverage is significantly lower than the income earned on a Trust’s longer-term investments acquired from such leverage proceeds, and therefore the holders of Common Shares (“Common Shareholders”) are the beneficiaries of the incremental net income.

However, in order to benefit shareholders, the return on assets purchased with leverage proceeds must exceed the ongoing costs associated with the leverage. If interest and other costs of leverage exceed a Trust’s return on assets purchased with leverage proceeds, income to shareholders is lower than if a Trust had not used leverage. Furthermore, the value of the Trusts’ portfolio investments generally varies inversely with the direction of long-term interest rates, although other factors can influence the value of portfolio investments. In contrast, the amount of each Trust’s obligations under its respective leverage arrangement generally does not fluctuate in relation to interest rates. As a result, changes in interest rates can influence the Trusts’ NAVs positively or negatively. Changes in the future direction of interest rates are very difficult to predict accurately, and there is no assurance that a Trust’s intended leveraging strategy will be successful.

The use of leverage also generally causes greater changes in each Trust’s NAV, market price and dividend rates than comparable portfolios without leverage. In a declining market, leverage is likely to cause a greater decline in the NAV and market price of a Trust’s shares than if the Trust were not leveraged. In addition, each Trust may be required to sell portfolio securities at inopportune times or at distressed values in order to comply with regulatory requirements applicable to the use of leverage or as required by the terms of leverage instruments, which may cause the Trust to incur losses. The use of leverage may limit a Trust’s ability to invest in certain types of securities or use certain types of hedging strategies. Each Trust incurs expenses in connection with the use of leverage, all of which are borne by shareholders and may reduce income to the shareholders. Moreover, to the extent the calculation of each Trust’s investment advisory fees includes assets purchased with the proceeds of leverage, the investment advisory fees payable to the Trusts’ investment adviser will be higher than if the Trusts did not use leverage.

Each Trust may utilize leverage through a credit facility or reverse repurchase agreements as described in the Notes to Financial Statements, if applicable.

Under the Investment Company Act of 1940, as amended (the “1940 Act”), each Trust is permitted to issue debt up to 33 1/3% of its total managed assets. A Trust may voluntarily elect to limit its leverage to less than the maximum amount permitted under the 1940 Act. In addition, a Trust may also be subject to certain asset coverage, leverage or portfolio composition requirements imposed by its credit facility, which may be more stringent than those imposed by the 1940 Act.

If a Trust segregates or designates on its books and records cash or liquid assets having a value not less than the value of a Trust’s obligations under a reverse repurchase agreement (including accrued interest), then such transaction is not considered a senior security and is not subject to the foregoing limitations and requirements imposed by the 1940 Act.

Overview

In general, the goal of each of the Trusts is to provide total return through a combination of current income and realized and unrealized gains (capital appreciation). The Trusts seek to pursue these goals primarily by investing in a portfolio of equity securities and also by employing a strategy of writing (selling) call and put options in an effort to generate current gains from option premiums and to enhance each Trust’s risk-adjusted return. Each Trust’s objectives cannot be achieved in all market conditions.

Each Trust primarily writes single stock covered call options and may also from time to time write single stock put options. When writing (selling) a covered call option, a Trust holds an underlying equity security and enters into an option transaction which allows the counterparty to purchase the equity security at an agreed-upon price (“strike price”) within an agreed-upon time period. The Trust receives cash premiums from the counterparties upon writing (selling) the option, which along with net investment income and net realized gains, if any, are generally available to support current or future distributions paid by the Trust. During the option term, the counterparty may elect to exercise the option if the market value of the equity security rises above the strike price, and the Trust is obligated to sell the equity security to the counterparty at the strike price, realizing a gain or loss. Premiums received increase gains or reduce losses realized on the sale of the equity security. If the option remains unexercised upon its expiration, the Trust realizes gains equal to the premiums received. Alternatively, an option may be closed out by an offsetting purchase or sale of an option prior to expiration. The Trust realizes a capital gain from a closing purchase or sale transaction if the premium paid is less than the premium received from writing the option. The Trust realizes a capital loss from a closing purchase or sale transaction if the premium received is less than the premium paid to purchase the option.

Writing covered call options entails certain risks, which include, but are not limited to, the following: an increase in the value of the underlying equity security above the strike price can result in the exercise of a written option (sale by a Trust to the counterparty) when the Trust might not otherwise have sold the security; exercise of the option by the counterparty may result in a sale below the current market value and a gain or loss being realized by the Trust; and limiting the potential appreciation that could be realized on the underlying equity security to the extent of the strike price of the option. The premium that a Trust receives from writing a covered call option may not be sufficient to offset the potential appreciation on the underlying equity security above the strike price of the option that could have otherwise been realized by the Trust. As such, an option over-writing strategy may outperform the general equity market in flat or falling markets but underperform in rising markets.

Option Over-Writing Strategy Illustration

To illustrate these concepts, assume the following: (1) a common stock purchased at and currently trading at $37.15 per share; (2) a three-month call option is written by a Trust with a strike price of $40 (i.e., 7.7% higher than the current market price); and (3) the Trust receives $2.45, or 6.6% of the common stock’s value, as a premium. If the stock price remains unchanged, the option expires and there would be a 6.6% return for the three-month period. If the stock were to decline in price by 6.6% (i.e., decline to $34.70 per share), the option strategy would “break-even” from an economic perspective resulting in neither a gain nor a loss. If the stock were to climb to a price of $40 or above, the option would be exercised and the stock would return 7.7% coupled with the option premium received of 6.6% for a total return of 14.3%. Under this scenario, the Trust loses the benefit of any appreciation of the stock above $40, and thus is limited to a 14.3% total return. The premium from writing the call option serves to offset some of the unrealized loss on the stock in the event that the price of the stock declines, but if the stock were to decline more than 6.6% under this scenario, the Trust’s downside protection is eliminated and the stock could eventually become worthless.

Each Trust intends to write covered call and other options to varying degrees depending upon market conditions. Please refer to each Trust’s Schedule of Investments and the Notes to Financial Statements for details of written options.

Derivative Financial Instruments

The Trusts may invest in various derivative financial instruments. These instruments are used to obtain exposure to a security, commodity, index, market, and/or other assets without owning or taking physical custody of securities, commodities and/or other referenced assets or to manage market, equity, credit, interest rate, foreign currency exchange rate, commodity and/or other risks. Derivative financial instruments may give rise to a form of economic leverage and involve risks, including the imperfect correlation between the value of a derivative financial instrument and the underlying asset, possible default of the counterparty to the transaction or illiquidity of the instrument. The Trusts’ successful use of a derivative financial instrument depends on the investment adviser’s ability to predict pertinent market movements accurately, which cannot be assured. The use of these instruments may result in losses greater than if they had not been used, may limit the amount of appreciation a Trust can realize on an investment and/or may result in lower distributions paid to shareholders. The Trusts’ investments in these instruments, if any, are discussed in detail in the Notes to Financial Statements.

Investment Objective

BlackRock Capital Allocation Trust’s (BCAT) (the “Trust”) investment objectives are to provide total return and income through a combination of current income, current gains and long-term capital appreciation. The Trust invests in a portfolio of equity and debt securities. Generally, the Trust’s portfolio will include both equity and debt securities. At any given time, however, the Trust may emphasize either debt securities or equity securities. The Trust utilizes an option writing (selling) strategy in an effort to generate current gains from options premiums and to enhance the Trust’s risk-adjusted returns.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

Performance

Returns for the period ended June 30, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

Due to the nature of the Trust’s mandate, performance is reviewed on an absolute return basis. The Trust has an unconstrained approach (i.e., flexibility to invest across all equity and fixed- income asset classes, spanning public and private markets). As such, the Trust is not managed specifically to a benchmark. The index returns listed above are for reference purposes only. Performance information below is expressed on a contribution to return basis.

Holdings in index-related equity futures (mainly as a risk-management strategy during periods of heightened market volatility) contributed to performance, as did positioning in the energy sector. Positioning in interest-rate derivatives had a positive impact on results in fixed income.

The Trust’s holdings in equities, particularly in the information technology, consumer discretionary and industrials sectors, detracted from performance. Positions in credit-sensitive investments were the primary detractors in bonds.

The Trust used derivatives, which may include options, futures, swaps and forward contracts, in an effort to enhance returns and manage the risk of adverse market movements. In the aggregate, the Trust’s use of derivatives contributed to performance. The Trust used an options overlay strategy in which calls were written on a portion of the portfolio’s holdings. The Trust’s options overlay strategy contributed to performance.

Describe recent portfolio activity.

The Trust’s allocation to equities decreased, with the largest reductions occurring in information technology, consumer discretionary, healthcare, financials, and industrials. The total allocation to fixed income also declined, with the largest reductions in high yield bonds and emerging market sovereign bonds. The Trust’s holdings in cash increased as result of these changes.

The use of leverage, primarily deployed within fixed income, decreased. The Trust uses leverage to seek to enhance both the income and total return of the portfolio.

Describe portfolio positioning at period end.

The Trust had a 40% weighting in equities. It had allocations to all sectors, with the largest absolute weightings in information technology, consumer discretionary, health care and financials. Within equities, the Trust used options as an additional source of income. As of June 30, 2022, the Trust had sold options on approximately 17% of the equity portion of the portfolio.

The Trust finished the period with a weighting of 54% in fixed income, comprised predominately of high yield bonds, securitized assets and to a lesser extent, investment-grade corporate bonds and emerging market sovereign bonds. The investment adviser sought to hold securities with attractive yields relative to the associated interest-rate risk.

The Trust held approximately 10.8% of its total assets in private investments.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments

Investment Objective

BlackRock ESG Capital Allocation Trust’s (the “Trust”) investment objectives are to provide total return and income through a combination of current income, current gains and long-term capital appreciation. The Trust will invest in a portfolio of equity and debt securities. Generally, the Trust’s portfolio will include both equity and debt securities. At any given time, however, the Trust may emphasize either debt securities or equity securities. In addition, the Trust may invest without limit in “junk bonds,” corporate loans and distressed securities. The Trust will invest at least 80% of its total assets in securities that, in the investment adviser’s assessment, meet certain environmental, social and governance (“ESG”) criteria. The Trust utilizes an option writing (selling) strategy in an effort to generate current gains from options premiums and to enhance the Trust’s risk-adjusted returns.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

Performance

Returns for the period ended June 30, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

Due to the nature of the Trust’s mandate, performance is reviewed on an absolute return basis. The Trust has an unconstrained approach (i.e., flexibility to invest across all equity and fixed-income asset classes, spanning public and private markets) with ESG considerations. As such, the Trust is not managed specifically to a benchmark. The index returns listed above are for reference purposes only. Performance information below is expressed on a contribution to return basis.

Positioning in interest-rate derivatives in fixed income contributed positively to performance. The Trust’s holdings in equities, particularly in the information technology, health care, industrials and consumer discretionary sectors, detracted from performance. Positions in credit-sensitive investments were the primary detractors in bonds.

The Trust used derivatives, which may include options, futures, swaps and forward contracts, in an effort to enhance returns and manage the risk of adverse market movements. In the aggregate, the Trust’s use of derivatives modestly contributed to performance. The Trust used an options overlay strategy in which calls were written on a portion of the portfolio’s holdings. The Trust’s options overlay strategy contributed to performance.

Given the current environment, the Trust sought to maintain an elevated exposure to cash equivalents as the team remains patient in deploying capital amid heightened market volatility. The Trust’s cash position did not have a material impact on performance.

Describe recent portfolio activity.

The Trust continued its initial ramp-up following its launch in September 2021, with about 83% of net assets invested across equity and fixed-income markets. The Trust’s allocation to equities fell slightly, mainly due to market movements, with the largest decreases in information technology, financials and utilities. This was partially offset by additions in health care and materials. The Trust’s fixed-income weighting increased, with the largest additions in investment-grade and high yield corporate bonds.

Describe portfolio positioning at period end.

The Trust had a 54% weighting in equities. It had allocations to all sectors, with the largest absolute weightings in information technology, health care, consumer discretionary and financials. Within equities, the Trust used options as an additional source of income. As of June 30, 2022, the Trust had sold options on approximately 12% of the equity portfolio.

The Trust finished the period with a weighting of 29% in fixed income, comprised predominately of investment-grade corporate bonds, high yield bonds and securitized assets. The investment adviser sought to hold securities with attractive yields relative to the associated interest-rate risk.

The Trust held approximately 3.5% of its total assets in private investments.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments