Armour is a city in and county seat of Douglas County, South Dakota, United States. The population was 699 at the 2010 census.
Armour was founded in 1885. The city was named after Philip Danforth Armour, who was founder of Armour and Company, a meat packing company. Contrary to popular belief, Armour was never home to a meat packing plant; the town was so named because Mr. Armour was also the chairman of the railroad that went through Armour and donated a bell to the local congregational church. The athletic teams of Armour High School were formerly known as the "Packers" in reference to the well known packing company, although today the high school plays its sports jointly with Tripp-Delmont High School as the "Armour/Tripp-DelmontNighthawks."
Armour is located at 43°19′10″N 98°20′50″W (43.319410, -98.347342).
According to the United States Census Bureau, the city has a total area of 0.95 square miles (2.46 km2), of which 0.94 square miles (2.43 km2) is land and 0.01 square miles (0.03 km2) is water.
Armour has been assigned the ZIP code 57313, and the FIPS place code 02260.
As of the census of 2010, there were 699 people, 325 households, and 181 families residing in the city. The population density was 743.6 inhabitants per square mile (287.1/km2). There were 378 housing units at an average density of 402.1 per square mile (155.3/km2).