St. Marys
- County:
- Ward County
- County Seat:
- No
- Area (mi²):
- 34.894
- State:
- North Dakota
St. Marys is located in Ward County, North Dakota. St. Marys has a 2025 population of 48 . St. Marys is currently declining at a rate of 0% annually and its population has decreased by -4% since the most recent census, which recorded a population of 50 in 2020.
The median age in St. Marys is 39.6 years: 35.9 years for males, and 41.3 years for females. For every 100 females there are 71.1 males.