Benacre NNR is a National Nature Reserve in Suffolk, England within The Broads National Park, maintained by English Nature.

It consists of three isolated broads in the River Waveney area:

They are situated between Kessingland, Wrentham and Southwold, close to the Suffolk coast.

There are extensive reed beds, woodlands and heathlands, also pits created by gravel extraction. Reed is farmed commercially for the thatching industry, whilst enabling the bearded reedling to find a habitat.

There are over 100 species of breeding birds, including marsh harrier, bearded reedling, water rail, and occasionally bittern. The flora includes sea kale, sea holly, and yellow-horned poppy.

Some of the ongoing work at the reserve is stopping the encroaching sea by digging new lagoons and establishing moe sea defences, and replacing the woodland lost to the sea.

Whilst the broads in Norfolk came about through peat digging in the Middle Ages, the Benacre broads are lakes formed in shallow valleys when glacial drift blocked off the outflow to the sea.