Coordinates: 48°34′58.80″N 104°11′52.80″W / 48.5830000°N 104.1980000°W
Dagmar is an unincorporated community in northeastern Sheridan County, Montana, United States. The town was established in 1906 by early Danish immigrants to the area.
Dagmar currently has a general store and a post office which operated since 1907. Dagmar's school closed in 1996.