Sant Quirze del Vallès (Catalan pronunciation: [ˌsaŋ ˈkiɾzə ðəl βəˈʎɛs]) is a town located in the comarca of the Vallès Occidental, province of Barcelona, Catalonia.

Sant Quirze is a residential town populated by approximately 20,000 people with a density of 1.432,27 hab/km², and has grown since the end of the 1990s onwards.

It shares borders with Sabadell, Rubí, Terrassa and Sant Cugat, among others, which are important towns within the Barcelona area, since they form Catalonia's most important industrial area and probably also Spain's.

In 1857, it was baptized with the name of San Quirico de Tarrasa, in a Spanish way, which was changed to Sant Quirze de la Serra and changed back again to the Spanish way after the war.

In 1976 the name changed to Sant Quirze del Vallès, which was officiated in 1983 with the disagreement of some of the population.