Chessel Bay is a 12.9-hectare (32-acre) Local Nature Reserve on the east bank of the River Itchen in Southampton in Hampshire.

[1][2] It is part of Solent and Southampton Water Ramsar site[3] and Special Protection Area,[4] and of Lee-on-The Solent to Itchen Estuary, which is a Site of Special Scientific Interest.

At low tide the mudflats are exposed attracting wading birds and wildfowl: curlew, oystercatchers and dunlin can be seen throughout the year.

At low tide, mudflats are exposed, and these attract feeding estuary birds.

The reserve suffers from high levels of plastic pollution due to its position on the bend of Itchen.