Uniao Sport Clube is a Portuguese sports club from Santiago do Cacem.
The men's football team plays in the I AF Setubal. The team played on the third-tier Segunda Divisao B in the first half of the 1990s. Their last stint in the Terceira Divisao lasted from 2002 to 2005.
In the Taca de Portugal, Uniao Santiago notably reached the fourth round in the 1992–93 and third round in 2018–19.