The name Siemion may refer to:
As a surname: Andrew Siemion (born 1980), American astrophysicist Łukasz Siemion (born 1985), Polish rower Wojciech Siemion (1928–2010), Polish stage and film actor
As a given name: Semyon Budyonny (1883–1973), also spelled Siemion Budionnyi, Soviet cavalryman, military commander, and politician Siemion Fajtlowicz (fl. 1967), Polish mathematician
See also Simeon