Oak Run is a census-designated place and resort community in Persifer and Copley townships, Knox County, Illinois, United States.

The development surrounds the 580-acre (2.3 km2) Spoon Lake, the largest man-made body of water in Central Illinois.

Other facilities include a swimming pool, lounge building, tennis courts, beaches and a 56-site campground.

Following the purchase of this acreage from 27 land owners, American Central commenced construction of Oak Run in 1971.

The lake first reached pool elevation in 1973 and is fed by Sugar Creek and natural springs.