Alexander is a city in McKenzie County, North Dakota, United States. The population was 223 at the 2010 census. Alexander was founded in 1905 and is named after early North Dakota politician Alexander McKenzie.
According to the United States Census Bureau, the city has a total area of 1.44 square miles (3.73 km2), of which 1.43 square miles (3.70 km2) is land and 0.01 square miles (0.03 km2) is water.
As of the census of 2010, there were 223 people, 100 households, and 60 families residing in the city. The population density was 155.9 inhabitants per square mile (60.2/km2). There were 120 housing units at an average density of 83.9 per square mile (32.4/km2). The racial makeup of the city was 91.5% White, 1.8% African American, 4.9% Native American, 0.4% from other races, and 1.3% from two or more races. Hispanic or Latino of any race were 4.9% of the population.
There were 100 households, of which 21.0% had children under the age of 18 living with them, 48.0% were married couples living together, 5.0% had a female householder with no husband present, 7.0% had a male householder with no wife present, and 40.0% were non-families. 32.0% of all households were made up of individuals, and 15% had someone living alone who was 65 years of age or older.