Olsztyn Voivodeship (Polish: województwo olsztyńskie) was an administrative division and unit of local government in Poland in the years 1945–75, and a new territorial division between 1975–1998, superseded by Warmian-Masurian Voivodeship. Its capital city was Olsztyn.

From 1945 to 1975 the Olsztyn Voivodeship covered a larger area.