Sinks Valley is a biological Site of Special Scientific Interest in Kesgrave, on the eastern outskirts of Ipswich in Suffolk, United Kingdom.
This site has diverse semi-natural habitats, with alder and oak woodland, a brook with fringing swamp, wet and dry grassland, spring fed fen and heath. Areas grazed by rabbits have a short turf rich in lichens, mosses and herbs. The nationally uncommon mossy stonecrop grows on paths.
The site is private property with no public access.