Arnaldo Tamayo Méndez (born January 29, 1942) was the first Cuban cosmonaut and the first person from an American country other than the USA to travel in space.

Born in Guantánamo, Tamayo graduated from the Air Force Academy and became a pilot in the Cuban Air Defence Force . He was selected as part of the seventh international programme for Intercosmos on March 1, 1978. His backup cosmonaut was fellow Cuban José López Falcón .

Tamayo, along with Soviet cosmonaut Yuri Romanenko, was launched into space as part of the Soyuz 38 from Baikonur Cosmodrome on September 18, 1980, at 19:11 UTC). After docking with Salyut 6, Tamayo and Romanenko conducted experiments in an attempt to find what caused space sickness, and perhaps even find a cure. After 124 orbits and 7 days, 20 hours and 43 minutes, Tamayo and Romanenko landed 180 km from Dzheskasgan . The landing was risky, as it was in darkness.

Following his career as a cosmonaut, Tamayo was made director of the Comités de Defensa de la Revolución.

Tamayo is married to Maria Lobaina and has two sons, Orlando (born 1968) and Arnaldo (born 1970). To date he has not been honoured with induction into the International Space Hall of Fame.