Adair is an unincorporated community and census-designated place (CDP) in McDonough County, Illinois, United States.

[4] Adair is in eastern McDonough County, along U.S. Route 136 (Main Street).

US 136 leads northwest 11 miles (18 km) to Macomb, the county seat, and southeast 28 miles (45 km) to Havana.

The Burlington Northern Santa Fe Railway runs through the east side of Adair.

This McDonough County, Illinois location article is a stub.