A clapper bridge is an ancient form of bridge found on the moors of Devon (Dartmoor and Exmoor) and in other upland areas of the United Kingdom including Snowdonia and Anglesey. It is formed by large flat slabs of granite or schist supported on stone piers (across rivers), or resting on the banks of streams. According to the Dartmoor National Park, the word 'clapper' derives from an Anglo-Saxon word, 'cleaca', meaning 'bridging the stepping stones'.

Although often believed to be of prehistoric origin, most were erected in medieval times, and some in later centuries. They are often situated close to a ford where carts could cross.

The finest example and the largest still to be complete, is to be found at Postbridge, on Dartmoor. Its slabs are over four metres (13ft) long, two metres (6ft 6in) wide and weigh over 8 tons each, making the bridge passable to a small cart. It was first recorded in 1380 and was built to facilitate the transportation of tin by pack horses to the stannary town of Tavistock.

Other larger clapper bridges, such as at Dartmeet and Bellever, have collapsed - their slabs swept away by floods, or raided for building or wall construction. However, there are many other smaller examples in existence on Dartmoor and still in use, such as those at Teignhead Farm (close to Grey Wethers stone circles), Scorhill and across the Wallabrook stream.