250px|right|thumb|The River Cerne at its source in [[Minterne Magna]]
The River Cerne is a river in Dorset, England, which rises in the Chalk hills of the Dorset Downs at Minterne Magna, between High Stoy and Dogbury Hill, flows down a valley through Cerne Abbas and Charminster, and flows into the River Frome in Dorchester. The Cerne Valley lies in the Dorset National Landscape.
Etymology
The name Cerne is derived from the Primitive Welsh *carn, "cairn, pile of stones," thus meaning "the stony stream." The pronunciation with soft 'c', instead of "chern" as would be expected (Old English *ċēarn), is suggested as being due to Anglo-Norman influence.
Course
The Cerne has been described as "a friendly river, for none of its delightful villages shun the stream". Another wrote, "The change from the sheep-grazed open downland landscape of the river's source to the intimate enclosed beauty of Minterne Gardens is quite magical". A 2008 report by the Wild Trout Trust stated that a fishery owned by the Gallia family is located near to Nether Cerne which had been recognised by a trust conservation award. The report concluded that "the habitat of the River Cerne was excellent, providing good quality habitat for all life stages of brown trout".
In the past, the river has over spilled into Cerne Abbas, however no river-related flooding has occurred since a relief scheme, involving a system of gullies and culverts, and a reservoir capable of holding 44,000,000 litres of floodwater, was commissioned in 1986.