Caylus (French pronunciation: [kajlys]; Languedocien: Cailutz) is a commune in the Tarn-et-Garonne department in the Occitanie region in southern France.

Caylus is famous for a castle built before 1176, and was owned by Raymond V of Toulouse at the time.

In 1562, the city was sacked by the troops Calvinists of Symphorien Durfort, lord of Duras.

In 1622, Louis XIII established headquarters here during the siege of Saint-Antonin.

(1813–1860), a French Catholic priest, Lazarite missionary, and traveller was born in Caylus.