Weston Fen is a 14-hectare (35-acre) biological Site of Special Scientific Interest north of Weston-on-the-Green in Oxfordshire.

[1][2] This site has diverse habitats, including a fast-flowing stream, species-rich, calcareous fen, willow carr, hazel woodland, limestone grassland and marshy grassland.

There are several rare species of beetle, such as Sphaerius acaroides, Eubria palustris, Silis ruficollis and Agabus biguttatus.

[3] The site is private land, but a public footpath runs through it.