The River Lemon is a 16-kilometre (9.9 mi) river in the county of Devon in southwest England. It is a tributary of the River Teign, starting on Dartmoor by Haytor, and ending in Lyme Bay. It rises on the south-east side of Dartmoor near Haytor, joins with the River Sig and the Langworthy Brook at Sigford, then passes the village of Bickington.