Boughton Fen is a 15.7-hectare (39-acre) biological Site of Special Scientific Interest east of Downham Market in Norfolk. it is common land registered to Boughton Parish Council.

This valley in a tributary of the River Wissey is covered by tall fen over most of the site, together with areas of scrub which provide a habitat for breeding birds. There are many uncommon species of moths, including the rare Perizoma sagittaria.

There is access to the site from Oxborough Road.