Leonid Denisovich Kizim (Кизим Леонид Денисович) (August 5, 1941 – June 14, 2010) was a Soviet cosmonaut. He was selected as a cosmonaut on October 23, 1965. Kizim flew as Commander on Soyuz T-3, Soyuz T-10 and Soyuz T-15, and also served as backup commander for Soyuz T-2. All together he spent 374 days 17 hours 56 minutes in space. On Soyuz T-15, he was part of the only crew to visit two space stations on one spaceflight (Mir and Salyut 7).