| Site of Special Scientific Interest | |
 The Marsh from the air | |
  Location within Cornwall  Marazion Marsh (England) | |
| Coordinates | 50°07′31″N 5°28′33″W / 50.1253°N 5.4758°W |
|---|---|
| Interest | Biological |
| Area | 63.3 hectares (0.6330 km2; 0.2444 sq mi) |
| Notification | 1951 |
Marazion Marsh is a Royal Society for the Protection of Birds (RSPB) reserve situated in a shallow river valley, half a kilometre to the west of Marazion, Cornwall, UK. It is separated from the coast by a shingle bar and small sand dune system and contains Cornwall's largest reed bed.