Sidbury is a large village and former civil parish north of Sidmouth, now in the parish of Sidmouth, in the East Devon district, in the county of Devon, England. In 2011 the built-up area had a population of 457. It is situated on the A375 road and the River Sid, which rises at Crowpits Covert and runs for 6 miles to Lyme Bay at Sidmouth. Above the village is Sidbury Castle, the site of an Iron Age hill fort.