Pitsford Water or Pitsford Reservoir is a 413 hectare reservoir and biological Site of Special Scientific Interest east of Brixworth in Northamptonshire. It is owned by Anglian Water, which manages it as a water park for walking, cycling, fishing, sailing and birdwatching. An area of 181 hectares north of the causeway which divides the reservoir is the Pitsford Water Nature Reserve, which is managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.