Eureka
- County:
- Lincoln County
- County Seat:
- No
- Area (mi²):
- 1.326
- State:
- Montana
Eureka is a town located in Lincoln County, Montana. Eureka has a 2026 population of 1,561. Eureka is currently growing at a rate of 1.56% annually and its population has increased by 12.3% since the most recent census, which recorded a population of 1,390 in 2020.