Upper Thurne Broads and Marshes is a 1,185.9-hectare (2,930-acre) biological Site of Special Scientific Interest north of Great Yarmouth in Norfolk, England.

[1][2] Part of it is a Nature Conservation Review site, Grade I,[3] and it is in the Norfolk Coast Area of Outstanding Natural Beauty.

[4] It is part of the Broadland Ramsar site[5] and Special Protection Area,[6] and The Broads Special Area of Conservation.

[7] Two areas, Hickling Broad and Martham Broad, are national nature reserves[8][9] managed by the Norfolk Wildlife Trust.

It has four lakes, Hickling Broad, Heigham Sound, Horsey Mere and Martham Broad, together with smaller water bodies, swamp, fen, woodland and grazing marsh.