The Yealm is a river in Devon in England that rises 1,411 feet above sea level on the Stall Moor mires of south Dartmoor and travels 12 miles to the sea, passing through Cornwood, Lee Mill and Yealmpton, a mid-sized village with a population of c.2,000 which is its largest settlement, before reaching its estuary which forms a ria bounded on its western side by Wembury.