Jan Mosdorf (30 May 1904 – 11 October 1943), was a Polish right-wing politician, director of the nationalist organization All-Polish Youth (Młodzież Wszechpolska, MW) and member of the far-right political party National Radical Camp (ONR). He also worked as a publicist, using the pseudonym Andrzej Witkowski. In 1943, Mosdorf was killed in the Auschwitz concentration camp.