| Quan Sơn district | |
| Settlement Type: | District |
| Native Name: | Huyện Quan Sơn |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Name1: | North Central Coast |
| Subdivision Type2: | Province |
| Subdivision Name2: | Thanh Hóa |
| Seat Type: | Capital |
| Seat: | Quan Sơn |
| Unit Pref: | Imperial |
| Area Total Km2: | 943 |
| Population As Of: | 2019 |
| Population Total: | 45,520 |
| Timezone: | UTC + 7 |
| Utc Offset: | +7 |
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.[1]