Castelsarrasin is a commune in the Tarn-et-Garonne department in Midi-Pyrénées region of France. The inhabitants are called Castelsarrasinois. The first signs of life in the town is from 961. The name, Castel Sarracenum, would indicate that the castle was built in the Saracen era. Castelsarrasin was the finish of Stage 17 in the 2007 Tour de France.