CJ7 (Chinese: 長江七號; Cantonese Yale: Cheung gong chat hou; lit. 'Yangtze 7') is a 2008 Hong Kong–Chinese science fiction comedy drama film co-written, co-produced, starring, and directed by Stephen Chow. It was released on January 31, 2008, in Hong Kong. It was also released on March 14, 2008, in the United States.

In August 2007 the film was given the title CJ7, a play on China's successful Shenzhou crewed space missions—Shenzhou 5 and Shenzhou 6. It was previously known by a series of working titles including Alien and most notably A Hope.

CJ7 was filmed in Ningbo, in the Zhejiang province of China.