Sant Martí de Tous is a municipality in the comarca of Anoia, in Catalonia, Spain. It is located in the province of Barcelona, within the autonomous community of Catalonia in the northeast of the country.
The municipality belongs to the Anoia comarca, a district in central Catalonia known for its inland, hilly terrain and its network of small towns and villages. As a municipality, Sant Martí de Tous forms part of the local administrative structure of the region.