Mamasa Regency (Indonesian: Kabupaten Mamasa) is one of the six regencies that make up the West Sulawesi Province, Indonesia, on the island of Sulawesi. It covers a land area of 3,005.88 km2. The population was 140,082 at the 2010 Census and 163,383 at the 2020 Census. Its capital is the town of Mamasa. The Mamasa people – which is a sub-group of the Toraja people – form the most common ethnic group.