Alexei Leonov was the first person to walk in space back in 1965. On March 18, 1965, he left his spacecraft for about 12 minutes during the Soviet Voskhod 2 mission, making him the first human to do a spacewalk.
Alexei Leonov: The Soviet cosmonaut who made history with the first spacewalk in 1965.
Yuri Gagarin: He was the first human in space (1961), but not the first to spacewalk.
Neil Armstrong: Famous for being the first human to walk on the Moon (1969).
Tereshkova: Valentina Tereshkova holds the title of the first woman in space (1963).