Quan Sơn is a district (huyện) of Thanh Hóa province in the North Central Coast region of Vietnam.

As of 2019 the district had a population of 45,520.

[1] The district covers an area of 943 km².

The district capital lies at Quan Sơn.

This article about a location in Thanh Hóa Province, Vietnam is a stub.