The Principia is an educational institution for Christian Scientists located on two campuses in the St. Louis, Missouri metropolitan area of the United States.

[1] Principia School, located in Town and Country,[2] West St. Louis County, serves students from early childhood through high school, and Principia College, located about thirty miles away, is on the bluffs overlooking the Mississippi River in Elsah, Illinois.

Founded by Mary Kimball Morgan, Principia School was officially opened in 1898 in St.

Principia School later moved to its current location in the St. Louis suburb of Town and Country, Missouri in 1959.

[6] Principia School follows a British-style organization and as such its schools are as follows: Principia College is a private liberal-arts undergraduate college located on the bluffs of the Mississippi River in Elsah, Illinois.