St. Mary township
- County:
- McLean County
- County Seat:
- No
- Area (mi²):
- 33.235
- State:
- North Dakota
St. Mary township is located in McLean County, North Dakota. St. Mary township has a 2026 population of 204. St. Mary township is currently growing at a rate of 0.99% annually and its population has increased by 2.51% since the most recent census, which recorded a population of 199 in 2020.
The median age in St. Mary township is 73 years: 73.4 years for males, and 72 years for females. For every 100 females there are 166.7 males.