Buin-e Sofla (, also Romanized as Bu'in-e Soflá, Buyen-e Soflá, and Buyen Soflá - all meaning "Lower Buin"; also known as Buyen-e Pa'in with similar meaning; also, simply Buyen) is a city in and capital of Nanur District, in Baneh County, Kurdistan Province, Iran. At the 2014 census, its population was 2200, in 206 families.