Hartline
- County:
- Grant County
- County Seat:
- No
- Area (mi²):
- 0.334
- State:
- Washington
Hartline is a town located in Grant County, Washington. Hartline has a 2026 population of 177. Hartline is currently declining at a rate of 0% annually and its population has decreased by -1.12% since the most recent census, which recorded a population of 179 in 2020.