Warmian-Masurian Voivodeship or Warmia-Masuria Province (in Polish: Województwo warmińsko-mazurskie, [[Wikipedia:IPA for Polish|[vɔjɛˈvut͡stfɔ var]]ˈmiɲskɔ maˈzurskʲɛ]), is a voivodeship (province) in northeastern Poland. Its capital and largest city is Olsztyn. The voivodeship has an area of 24,192 km² (9,341 sq mi) and a population of 1,427,091 (as of 2006).

The Warmian-Masurian Voivodeship was created on January 1, 1999, from the entire Olsztyn Voivodeship, the western half of Suwałki Voivodeship and part of Elbląg Voivodeship, pursuant to the Polish local government reforms adopted in 1998. The province's name derives from two historic regions, Warmia and Masuria.

The province borders the Podlaskie Voivodeship to the east, the Masovian Voivodeship to the south, the Kuyavian-Pomeranian Voivodeship to the south-west, the Pomeranian Voivodeship to the west, the Vistula Lagoon to the northwest, and the Kaliningrad Oblast (an exclave of Russia) to the north. The region contains the southern part of the historic Prussian province of East Prussia, which was divided between Poland and the Soviet Union (and hence, today Russia) after the Second World War. Following the defeat of Nazi Germany, nearly all indigenous German-speaking inhabitants were forcefully expelled by the newly Soviet appointed Polish Communist national government to what would become West and East Germany. Today, a small German-speaking minority is still present in the region.