Grupo Sportivo de Loures is a Portuguese football club located in Loures, Portugal.

Loures was founded on 13 August 1913 by local footballers who used to play in a plot of land called Casaréus in Loures.

Their first ever game was a 3–1 friendly win over Sporting CP.

In the 1950s, the club added facilities for cycling, athletics, table tennis, and roller hockey.

[1] Castrense's colours are yellow and black.