Ennis is a town in Madison County, Montana, United States, in the southwestern part of the state. The population was 838 at the 2010 census.
The town is flanked by Tobacco Root Mountains to the northwest, the Gravelly Range to the southwest and the Madison Range to the east. Approximately 12 miles (19 km) north of town, the Madison Dam creates Ennis Lake at the head of Bear Trap Canyon. A large “E” has been placed in a hill west of the town at this location: 45°21′02″N 111°44′52″W / 45.3505°N 111.7478°W / 45.3505; -111.7478 (Ennis)
According to the United States Census Bureau, the town has a total area of 0.79 square miles (2.05 km), of which, 0.78 square miles (2.02 km) is land and 0.01 square miles (0.03 km) is water.
As of the census of 2010, there were 838 people, 416 households, and 207 families residing in the town. The population density was 1,074.4 inhabitants per square mile (414.8/km). There were 527 housing units at an average density of 675.6 per square mile (260.9/km). The racial makeup of the town was 96.9% White, 0.1% African American, 0.8% Native American, 0.2% Asian, 0.5% from other races, and 1.4% from two or more races. Hispanic or Latino of any race were 1.9% of the population.
There were 416 households of which 20.4% had children under the age of 18 living with them, 36.8% were married couples living together, 9.9% had a female householder with no husband present, 3.1% had a male householder with no wife present, and 50.2% were non-families. 42.5% of all households were made up of individuals and 20.4% had someone living alone who was 65 years of age or older. The average household size was 1.91 and the average family size was 2.60.
The median age in the town was 49.8 years. 15.8% of residents were under the age of 18; 6% were between the ages of 18 and 24; 22.2% were from 25 to 44; 30.7% were from 45 to 64; and 25.3% were 65 years of age or older. The gender makeup of the town was 49.4% male and 50.6% female.
As of the census of 2000, there were 840 people, 367 households, and 219 families residing in the town. The population density was 1,240.2 people per square mile (476.9/km). There were 434 housing units at an average density of 640.8 per square mile (246.4/km). The racial makeup of the town was 97.98% White, 0.48% from other races, and 1.55% from two or more races. Hispanic or Latino of any race were 0.71% of the population.
There were 367 households out of which 27.2% had children under the age of 18 living with them, 46.9% were married couples living together, 9.5% had a female householder with no husband present, and 40.1% were non-families. 36.0% of all households were made up of individuals and 11.2% had someone living alone who was 65 years of age or older. The average household size was 2.20 and the average family size was 2.87.
In the town, the population was spread out with 24.3% under the age of 18, 5.7% from 18 to 24, 23.0% from 25 to 44, 26.3% from 45 to 64, and 20.7% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 90.9 males. For every 100 females age 18 and over, there were 94.5 males.
The median income for a household in the town was $30,735, and the median income for a family was $38,542. Males had a median income of $30,956 versus $16,875 for females. The per capita income for the town was $17,310. About 7.7% of families and 11.9% of the population were below the poverty line, including 10.9% of those under age 18 and 11.7% of those age 65 or over.