Armstrong is a city in Emmet County, Iowa, United States.

[3] It was named after Thomas Armstrong, who first arrived in the area near the West Fork Des Moines River to trap.

In February 2021, Armstrong's mayor, Gregory Wayne Buum; police chief, Craig Juan Merrill; city clerk, Tracie Lang; and former city clerk Connie Marie Thackery were charged with 21 felony and misdemeanor counts, including fraud, misappropriation of funds, and assault with a dangerous weapon.

[7] According to the United States Census Bureau, the city has an area of 0.88 square miles (2.28 km2), all land.

There were 436 housing units at an average density of 493.2 per square mile (190.4/km2).

There were 439 housing units at an average density of 498.9 per square mile (192.6/km2).

The racial makeup of the city was 97.8% White, 0.4% Native American, 0.4% Asian, and 1.3% from two or more races.

33.0% of all households were made up of individuals, and 17.4% had someone living alone who was 65 years of age or older.

33.4% of all households were made up of individuals, and 19.0% had someone living alone who was 65 years of age or older.

The former formed on July 1, 1979, with the merger of the Armstrong and Ringsted school districts.