Newtown
- County:
- Sullivan County
- County Seat:
- No
- Area (mi²):
- 0.253
- State:
- Missouri
Newtown is a town located in Sullivan County, Missouri. Newtown has a 2026 population of 110. Newtown is currently declining at a rate of -0.9% annually and its population has decreased by -4.35% since the most recent census, which recorded a population of 115 in 2020.