Association Culturelle et Sportive du Ksar (Arabic: الجمعية الثقافية و الرياضية للكصر) known as ACS Ksar is a Mauritanian football club based in Nouakchott the capital of the Mauritania.

The club won two consecutive titles in 1993, Ksar first appeared at the continental level in 1992.

Ksar won their recent championship title in 2004 and a year later entered into their recent continental competition and their first and only as the CAF Champions League.

Ksar appeared once in the Arab Champions' League (now the UAFA Club Cup) in the 2005–06 season.

Currently the team plays at the 10,000 capacity Stade Olympique (Nouakchott).