St Nicolas' Church is an Anglican church in Old Shoreham, an ancient inland settlement that is now part of the town of Shoreham-by-Sea in the district of Adur, one of seven local government districts in the English county of West Sussex. It was founded on a riverside site by Anglo-Saxons at the start of the 10th century, possibly on the site of a 5th-century predecessor. Some Saxon-era structural elements remain despite 12th-century additions made when Shoreham became prosperous, further extension in the 14th century and a Victorian restoration. The cruciform structure, with its solid central tower, features some unusual Norman-era carving. English Heritage has listed it at Grade I for its architectural and historical importance.