Sa Pa is subdivided to 16 commune-level subdivisions, including the 6 wards of: Cau May, Ham Rong, O Quy Ho, Fansipan, Sa Pa, Sa Pa and 10 rural communes of: Ban Ho, Hoang Lien, Lien Minh, Muong Bo, Muong Hoa, Ngu Chi Son, Ta Phin, Ta Van, Thanh Binh and Trung Chai.
As of 2018, the town had a population of 61,498. The town covers an area of 677 km2. The town capital lies at Sa Pa ward.