Casey is a city in Clark and Cumberland counties in the U.S. state of Illinois. The population was 2,942 at the 2000 census.
The Cumberland County portion of Casey is part of the Charleston–Mattoon Micropolitan Statistical Area.
Casey is located at 39°17′58″N 87°59′24″W / 39.29944°N 87.99°W / 39.29944; -87.99 (39.299543, -87.990056). Most of the city lies in Clark County, although a small portion extends into Cumberland County. In the 2000 census, 2,940 of Casey's 2,942 residents (99.9%) lived in Clark County and 2 (0.1%) lived in Cumberland County.