424B3

Filed pursuant to Rule

424(b)(3)

Registration

No. 333-279051

WESTERN ASSET MORTGAGE OPPORTUNITY FUND INC.

SUPPLEMENT DATED FEBRUARY 13, 2026 TO THE PROSPECTUS AND

STATEMENT OF ADDITIONAL INFORMATION DATED AUGUST 28, 2024

Effective as of the date of this supplement, the following supplements and, to the extent inconsistent with, supersedes such information in the Fund’s Prospectus and Statement of Additional Information (“SAI”):

Prospectus

The first paragraph on the cover page of the Prospectus is removed entirely and replaced as follows:

The Fund.

Western Asset Mortgage Opportunity Fund Inc. (the “Fund”) is a diversified,

closed-end

management investment company incorporated under the laws of the State of Maryland. The Fund was previously classified as a

non-diversified

management investment company under the Investment Company Act of 1940, as amended (the “1940 Act”). As a result of ongoing operations, the Fund is now classified as a diversified management investment company. This means that with respect to 75% of the Fund’s total assets, no more than 5% of the Fund’s total assets may be invested in any one issuer or own more than 10% of the outstanding voting securities of such issuer (except, in each case, excepting cash and cash items, U.S. government securities, and securities of other investment companies). The Fund may not resume operating in a

non-diversified

manner without first obtaining shareholder approval in accordance with the 1940 Act.

The second paragraph titled “The Fund” on page 1 of the Prospectus under “Prospectus Summary” is removed entirely and replaced as follows:

The Fund

Western Asset Mortgage Opportunity Fund Inc., a Maryland corporation (the “Fund”), is a diversified,

closed-end

management investment company. The Fund was previously classified as a

non-diversified

manner without first obtaining shareholder approval in accordance with the 1940 Act.

The paragraph titled “

“Non-Diversification

Risk”. on page 18 of the Prospectus under “Prospectus Summary” is deleted in its entirety.

The section titled “The Fund” on page 30 of the Prospectus is removed entirely and replaced as follows:

THE FUND

The Fund is a diversified,

closed-end

management investment company registered under the 1940 Act. The Fund was previously classified as a

non-diversified

management investment company under 1940 Act. As a result of ongoing operations, the Fund is now classified as a diversified management investment company. This means that with respect to 75% of the Fund’s total assets, no more than 5% of the Fund’s total assets may be invested in any one issuer or own more than 10% of the outstanding voting securities of such issuer (except, in each case, excepting cash and cash items, U.S. government securities, and securities of other investment companies). The Fund was incorporated as a Maryland corporation on December 11, 2009, pursuant to the Charter. The Fund’s principal executive office is located at One Madison Avenue, 17th Floor, New York, New York 10010, and its telephone number is (888)

777-0102.

The first paragraph under “Risks” on page 50 of the Prospectus is removed entirely and replaced as follows:

RISKS

The Fund is a diversified,

closed-end

management investment company designed primarily as a long-term investment and not as a trading vehicle. In accordance with the requirements of the 1940 Act, the Fund reclassified its diversification status from

non-diversified

to diversified. Diversification does not assure against market loss. The Fund is not intended to be a complete investment program and, due to the uncertainty inherent in all investments, there can be no assurance that the

Fund

will achieve its investment objectives. The Fund’s performance and the value of its investments will vary in response to changes in interest rates, inflation, the financial condition of a security’s issuer, ratings on a security and other market factors. Your securities at any point in time may be worth less than you invested, even after taking into account the reinvestment of Fund dividends and distributions. Below are the principal risks associated with an investment in the Fund.

The paragraph titled

“Non-Diversification

Risk.” on page 78 of the Prospectus under the section titled “Risks” is deleted in its entirety.

SAI

The first paragraph on the cover page of the SAI is removed and replaced as follows:

Western Asset Mortgage Opportunity Fund Inc. (the “Fund”) is a diversified,

closed-end

management investment company. The Fund was previously classified as a

non-diversified

manner without first obtaining shareholder approval in accordance with the 1940 Act.

SEC Form 424B3 filed by Western Asset Mortgage Opportunity Fund Inc.