| Official Name: | Lake Mary Ronan, Montana |
| Settlement Type: | Census-designated place |
| Pushpin Map: | Montana#USA |
| Pushpin Label: | Lake Mary Ronan |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Montana |
| Subdivision Type2: | County |
| Subdivision Name2: | Lake |
| Unit Pref: | Imperial |
| Area Footnotes: | [1] |
| Area Total Km2: | 2.72 |
| Area Land Km2: | 2.72 |
| Area Water Km2: | 0.00 |
| Area Total Sq Mi: | 1.05 |
| Area Land Sq Mi: | 1.05 |
| Area Water Sq Mi: | 0.00 |
| Population As Of: | 2020 |
| Population Total: | 53 |
| Population Density Km2: | 19.50 |
| Population Density Sq Mi: | 50.52 |
| Timezone: | Mountain (MST) |
| Utc Offset: | -7 |
| Timezone Dst: | MDT |
| Utc Offset Dst: | -6 |
| Elevation M: | 1155 |
| Coordinates: | 47.9244°N -114.3797°W |
| Postal Code Type: | ZIP code |
| Area Code: | 406 |
| Blank Name: | FIPS code |
| Blank Info: | 30-41910 |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 2583821 |
Lake Mary Ronan is a census-designated place (CDP) in Lake County, Montana, United States. The population was 65 at the 2010 census.[2] The CDP is in northwestern Lake County, along the northern and eastern shores of Lake Mary Ronan, and includes the populated places of Lake Mary Ronan, Melton, and Sipes, as well as Lake Mary Ronan State Park. It is 8miles northwest of U.S. Route 93 at Dayton, and northwest of Polson, the Lake county seat.
According to the U.S. Census Bureau, the CDP has an area of 2.7sqkm, of which 1796order=flipNaNorder=flip, or 0.07%, are water.[3]