| Maksim Petrovich Mager | |
| Native Name: | Максим Петрович Магер |
| Birth Date: | 1897 |
| Birth Place: | Mogilev Governorate, Russian Empire |
| Death Date: | 16 October 1941 |
| Death Place: | Soviet Union |
| Allegiance: | Soviet Union |
| Branch: | Soviet Red Army |
| Rank: | komkor |
| Serviceyears: | 1918–1938 |
| Battles: | Russian Civil War |
Maksim Petrovich Mager (Russian: Максим Петрович Магер; 1897 – 16 October 1941) was a Soviet komkor. He was born in what is now Belarus. He fought in the Soviet Red Army during the Russian Civil War. He was a recipient of the Order of Lenin (February 22, 1938) and the Order of the Red Banner.
During the Great Purge, Mager was arrested on September 10, 1938, and released on 9 February 1940. He was later re-arrested on 28 April 1941. As part of the Purge of the Red Army in 1941, he was sentenced to death by the Military Collegium of the Supreme Court of the Soviet Union and executed during the Battle of Moscow.