The Steart Peninsula (grid reference ST274459) is a peninsula in Somerset, England. At its outermost tip is Fenning Island (now joined to the mainland), at the tip of which is Stert Point (sometimes spelt Steart Point). North of Stert Point lies Stert Island, which was joined to the peninsula until about 1798. The peninsula consists largely of low-lying flat farmland, and projects northwards on the west side of Stockland Reach, the lower stretches of the estuary of the River Parrett.
The main settlement on the peninsula is the village of Steart, but two other villages, and Otterhampton sit at the peninsula's base. A single minor road links the village of Steart to these other villages. The River Parrett Trail runs along the peninsula.
West of the peninsula are the village of Stolford and Hinkley Point, and to the south is the village of Combwich.
There are two nature reserves on the peninsula. A third reserve is being developed by the Royal Society for the Protection of Birds.
Bridgwater Bay, a National Nature Reserve, lies on the northern side of the peninsula. The reserve includes the largest area of salt marsh in Somerset, and large expanses of mudflats exposed at low tide, important feeding and roosting sites for waterfowl and wading birds. There are four bird hides in the north of the reserve, near the tip of the peninsula. Adjoining the reserve are three coastal commons — from west to east these are Catsford Common, Wall Common and Steart Common.