Jan Mosdorf (30 May 1904, Warsaw - 11 October 1943, Auschwitz), was a Polish right-wing politician, director of the nationalist organization All-Polish Youth (Mlodziez 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 .