6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

under the Securities Exchange Act of 1934

For the month of November 2025

Commission File Number: 001-35942

LightInTheBox Holding Co., Ltd.

4 Pandan Crescent #03-03

Singapore (128475)

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

x Form 20-F                      ¨ Form 40-F

INFORMATIONCONTAINED IN THIS REPORT ON FORM 6-K

On November 25, 2025, LightInTheBox Holding Co., Ltd. (the “Company”) made available to its shareholders a convening notice to the Company’s annual general meeting. The annual general meeting is expected to take place on December 19, 2025, at 10:00 a.m. local time at 21st Floor, Lane 666, Haiyang West Road, Pudong New Area, Shanghai, China. A copy of the press release and the annual general meeting notice are attached as Exhibit 99.1 and 99.2 to this Report on Form 6-K.

The information contained in this Report on Form 6-K and Exhibit 99.1 and 99.2 to this Report on Form 6-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or incorporated by reference in any filing under the Securities Act of 1933, as amended, unless expressly set forth by specific reference in such a filing.

EXHIBIT INDEX

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: November 25, 2025

3

Exhibit 99.1

LightInTheBox to Hold 2025 Annual GeneralMeeting on December 19, 2025

Singapore, November 25, 2025 /PRNewswire/ -- LightInTheBox Holding Co., Ltd. (NYSE: LITB) (“LightInTheBox” or the “Company”), a global specialty retailer, today announced it will hold its 2025 annual general meeting of shareholders at 21st Floor, Lane 666, Haiyang West Road, Pudong New Area, Shanghai, China on December 19, 2025 at 10:00 a.m., local time.

No proposal will be submitted for shareholder approval at the annual general meeting. Instead, the annual general meeting will serve as an open forum for shareholders to discuss Company affairs with management.

The board of directors of the Company has fixed the close of business on December 5, 2025 as the record date (the “Record Date”) for determining the shareholders entitled to receive notice of the annual general meeting or any adjournment or postponement thereof. Owners and holders of the Company’s ADSs on the Record Date are welcome to attend the annual general meeting in person with valid proof of identification and ADS ownership as of the close of business on the Record Date. Those who hold ADSs indirectly through a brokerage firm, bank or other financial institution should contact their brokerage firm, bank or other financial institution for a letter or brokerage statement confirming their ADS ownership as of such date.

The Company has filed its annual report on Form 20-F, including its audited financial statements for the financial year ended December 31, 2024, with the U.S. Securities and Exchange Commission (the “SEC”). The Company’s annual report can be accessed on the Company’s website at https://ir.ador.com, as well as on the SEC's website at http://www.sec.gov. Shareholders may request a hard copy of the Company's annual report, free of charge, by contacting the Company at ir@ador.com.

About LightInTheBox Holding Co., Ltd.

LightInTheBox is a global specialty retail company, providing a diverse range of affordable lifestyle products directly to consumers worldwide since 2007. In 2024, the Company shifted its focus to apparel design and launched its first proprietary brand, Ador.com, to meet the growing global demand for accessible higher-end fashion. Ador.com specializes in designer-quality clothing for women aged 35-55 at competitive prices and operates design studios and sample shops in both the U.S. and China, including a boutique and design studio in Campbell, California. Additionally, LightInTheBox offers a comprehensive suite of services to e-commerce companies, including advertising, supply chain management, payment processing, order fulfillment, and shipping and delivery solutions.

For more information, please visit https://ir.ador.com.

Investor Relations Contact

Investor Relations

LightInTheBox Holding Co., Ltd.

Email: ir@ador.com

Exhibit 99.2

LIGHTINTHEBOX HOLDING CO., LTD.

(incorporated in the Cayman Islands with limitedliability)

NOTICE OF ANNUAL GENERAL MEETING

to Be Held on December 19, 2025

NOTICE IS HEREBY GIVENthat an Annual General Meeting (“AGM”) of LightInTheBox Holding Co., Ltd. (the “Company”) will be held at 21st Floor, Lane 666, Haiyang West Road, Pudong New Area, Shanghai, China on December 19, 2025 at 10:00 a.m., local time.

No proposal will be submitted for shareholder approval at the AGM. Instead, the AGM will serve as an open forum for shareholders to discuss Company affairs with management.

The board of directors of the Company has fixed the close of business on December 5, 2025 as the record date (the “Record Date”) for determining the shareholders entitled to receive notice of the AGM or any adjournment or postponement thereof.

The Company has filed its annual report on Form 20-F, including its audited financial statements for the financial year ended December 31, 2024, with the U.S. Securities and Exchange Commission (the “SEC”). The Company’s annual report can be accessed on the Company’s website at https://ir.ador.com, as well as on the SEC’s website at http://www.sec.gov. Shareholders may request a hard copy of the Company’s annual report, free of charge, by contacting the Company at ir@ador.com.

By Order of the Board of Directors,

/s/Jian He

Chief Executive Officer

Singapore

November 25, 2025