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

OF THE SECURITIES EXCHANGE ACT OF 1934

For the month of January 2015

Commission File Number: 001-34271

CHANGYOU.COM LIMITED

(Exact name of registrant as specified in its charter)

Changyou Creative Industrial Park

65 Bajiao East Road, Shijingshan District

Beijing 100043

People’s Republic of China

(Address of principal executive office)

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

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):  ¨    No  x

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):  ¨    No  x

Mr. Tao Wang resigned as a member of the board of directors of the registrant, effective January 15, 2015. As a result of Mr. Wang’s resignation, the board of directors of the registrant currently consists of Dr. Charles Zhang, Dave De Yang, Dr. Xiao Chen and Charles Chan.

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 hereunto duly authorized.

Date: January 26, 2015