The Polish census of 1931 or Second General Census in Poland was the second census taken in sovereign Poland during the interwar period, performed on December 9, 1931 by the Main Bureau of Statistics. It established that Poland's population amounted to almost 32 million people.

The Wilno Voivodeship was one of 16 Voivodeships in the Second Polish Republic, with the capital in Wilno. The jurisdiction was created in 1926 and populated predominantly by Poles, with notable minorities of Belarusians, Jews and Lithuanians. Before 1926, the voivodeship's area was known as the Wilno Land; it had the same boundaries and was also within the contemporary borders of Poland at the time.