Irwin is a city in Bonneville County, Idaho, United States. It is part of the Idaho Falls, Idaho Metropolitan Statistical Area. The population was 157 at the 2000 census.
Irwin is located at 43°23′18″N 111°16′5″W / 43.38833°N 111.26806°W / 43.38833; -111.26806 (43.388220, -111.268118).
According to the United States Census Bureau, the city has a total area of 2.1 square miles (5.5 km²), all of it land.