Gemini 10 was a 1966 crewed spaceflight in NASA's Gemini program. It was the 8th crewed Gemini flight, the 16th crewed American flight, and the 24th spaceflight of all time. During the mission, flown by future STS-1 Commander John Young and future Apollo 11 Command Module Pilot Michael Collins, Collins became the first person to perform two extravehicular activities.

Project Gemini was the second United States human spaceflight program to fly. Conducted after the first American manned space program, Project Mercury, while the Apollo program was still in early development, Gemini was conceived in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual astronauts flew low Earth orbit (LEO) missions during 1965 and 1966.