Unión Sporting Club was a Spanish football team based in Vigo, in the autonomous community of Galicia.

In the 1933–34 season, the club won the Tercera División, and disputed one campaign in Segunda División, finishing last in its group.

In 1937, Unión SC was disbanded, mainly due to the Spanish Civil War.

The club did not return to an active status, but the club's board and players joined Football Club Vigués in 1939, acting mainly as Celta de Vigo's reserve team.

This article about a Spanish association football club is a stub.