| Yên Định District | |
| Settlement Type: | District |
| Native Name: | Huyện Yên Định |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Name1: | North Central Coast |
| Subdivision Type2: | Province |
| Subdivision Name2: | Thanh Hóa |
| Seat Type: | Capital |
| Seat: | Quán Lào |
| Unit Pref: | Imperial |
| Area Total Km2: | 216 |
| Population As Of: | 2003 |
| Population Total: | 172,527 |
| Timezone: | UTC + 7 |
| Utc Offset: | +7 |
Yên Định is a rural district of Thanh Hóa province in the North Central Coast region of Vietnam. As of 2003 the district had a population of 172,527.[1] The district covers an area of 216 km². The district capital lies at Quán Lào.[1]