Fleet Pond is a biological Site of Special Scientific Interest in Fleet in Hampshire. It is also a Local Nature Reserve. Located on the northern edge of the town of Fleet in northeastern Hampshire, the 'pond', at 21 hectares (52 acres), is Hampshire's largest freshwater lake. The Reserve’s reed beds, marshes, heathland and woodland provide sanctuary for a rich and diverse community of animal and plant life, including many that are no longer to be found in an ordered, farmed countryside.
The total area of the Reserve is 141 acres (0.57 km2) of which 118 acres (0.48 km2) is designated as a Site of Special Scientific Interest (SSSI). This applies to the wetlands, the lake and the dry heathland.