Thanh Sơn is a rural district located in the Phú Thọ province within the Northeast region of Vietnam. The district serves as the administrative seat for its namesake town, which functions as the district capital.
The district covers a total area of 1,309 km2 and was recorded as having a population of 187,700 in 2003. A notable geographical feature within the district is the Xuân Sơn National Park.