Cattawade Marshes is an 88.2-hectare (218-acre) biological Site of Special Scientific Interest between East Bergholt and Manningtree in Essex and Suffolk, England.

[1][2] It is managed by the Royal Society for the Protection of Birds.

[3] It is a Ramsar wetland of international importance,[4] and part of the Stour and Orwell Special Protection Area, and the Dedham Vale Area of Outstanding Natural Beauty.

[5] The site is a marsh area between two arms of the River Stour.

It is of major importance for breeding birds, especially waders and wildfowl, such as Shoveler, Teal, Tufted Duck and Water Rail.