Thetford is a town in Orange County, Vermont, United States in the Connecticut River Valley. The population was 2,617 at the 2000 census. Villages within the town include East Thetford, North Thetford, Thetford Hill, Thetford Center, Rices Mills, Union Village, and Post Mills. The town office is in Thetford Center. .
Thetford is home to Thetford Academy, Vermont's oldest secondary school. Girl Scouts of the Green and White Mountains, formerly Swift Water Girl Scout Council, also has a summer residential camp here called Camp Farnsworth. Camp Farnsworth originally started under private ownership by Chelebe and Madama Farnsworth in 1909 when it was called Camp Hanoum.