The River Coln is a river in Gloucestershire, England. It rises at Charlton Abbotts, Gloucestershire southeast of Cheltenham, and flows through the Cotswold Hills, via Bibury, Coln St Aldwyns and Fairford, Southeast to the River Thames. It joins the Thames at Lechlade, Gloucestershire, where it shares a confluence with the Thames and Severn Canal, by The Round House Footbridge.
Extensive gravel pits that are now redundant, lying between Fairford and Lechlade, form the Eastern component of the Cotswold Water Park, which is fed and drained by the Coln.
The river is host to many species of freshwater fish.