Sumar (Persian: سومار; also Romanized as Sūmār, Soormar, and Sowmār) is a city and capital of Sumar District, in Qasr-e Shirin County, Kermanshah Province, Iran. At the 2006 census, its population was 20, in 15 families, making it Iran's least populous settlement with city status. The village is populated by Kurds.