Irwin is a city in Shelby County, Iowa, United States, along the West Nishnabotna River.

[3] The Western Town Lot Company established Irwin in 1881.

[6] In 1963, two United States Air Force B-47E bombers based at Schilling Air Force Base near Salina, Kansas, collided over western Iowa on August 19 and crashed several miles apart near Irwin.

[7] According to the United States Census Bureau, the city has a total area of 0.60 square miles (1.55 km2), all of it land.

There were 178 housing units at an average density of 304.1 per square mile (117.4/km2).

Hispanic or Latino persons of any race comprised 3.1% of the population.

There were 185 housing units at an average density of 308.3 per square mile (119.0/km2).

37.6% of all households were made up of individuals, and 20% had someone living alone who was 65 years of age or older.

There were 180 housing units at an average density of 302.1 per square mile (116.6/km2).

32.1% of all households were made up of individuals, and 19.0% had someone living alone who was 65 years of age or older.