The school was founded in 1875 as the "Salt Lake Collegiate Institute", a prep school under the supervision of the First Presbyterian church of Salt Lake City.

At that time, many protestant denominations flocked to Salt Lake City in order to try to "save" people who belonged to what they considered a cult. Westminster is the only remaining vestage of a trend in the late 1800s in which the Protestants set up private primary and secondary schools and offer free tuition to Mormon children in order to try to convert them out of Mormonism.

College level classes were first offered in 1897 as "Sheldon Jackson College". It was given that name after a Presbyterian minister and its primary benefactor, Sheldon Jackson. High school level classes ceased to be offered in 1945. Westminster severed its ties to the Presbyterian church in 1974.

The college changed its name to "Westminster College" in 1902 to better reflect a more general protestant education. The name is derived from the Westminster Confession of Faith, a Presbyterian confession of faith, which, in turn, was named for a London suburb where it was devised.

Westminster was the first accredited two year junior college in Utah. It then underwent changes to become a liberal arts institution in 1949.

Originally located in downtown Salt Lake City, the college moved to its present campus on 27 acres (109,000 m²) in the Sugar House neighborhood of the city.

The current president of Westminster College is Dr. Michael S. Bassis, appointed in 2002.