George Eugene Belknap (22 January 1832 – 7 April 1903) was a rear admiral in the United States Navy.

Belknap was the senior officer present during the riots following David Kalākaua's election as the King of Hawaii in 1874.

At the time, he was serving as commander of the sloop-of-war Tuscarora on a mission to take deep-sea soundings in the North Pacific to help identify the best route for a submarine cable between the United States and Japan.

On 7 April 1903, he died at Key West, Florida while on a working vacation to advise the Navy Department on a potential naval base location.

A portrait of Admiral Belknap is on display in Luce Hall at the United States Naval War College in Newport, Rhode Island.