Union Sportive Monastirienne, commonly known as US Monastir, is a Tunisian professional basketball club based in Monastir. Established in 1959, the team plays in the Pro A the first division league in Tunisia and has won seven national championships. Monastir also plays in the Basketball Africa League (BAL) since the inaugural season in 2021. Home games are played in the Mohamed-Mzali Sports Hall.

Monastir, also called Mestir, is a city on the central coast of Tunisia, in the Sahel area, some 20 kilometres south of Sousse and 162 kilometres south of Tunis. Traditionally a fishing port, Monastir is now a major tourist resort. Its population is about 93,306. It is the capital of Monastir Governorate.