The high school opened in 1872 a new high school. This building is the current city hall.
Somerville English High School opened in 1895 and still stands as the Central Wing, or B Building, of the current high school. It provided classical and general education.
The Somerville Free High School became the Somerville Latin School, so Somerville had twin high schools next to each other on Central Hill. Somerville's twin high schools were presented in educational exhibits at the 1900 Paris World's Fair and the 1904 St. Louis World's Fair.
In 1911, the twin schools merge to become Somerville High School. Boys' Vocational High School opened in 1910. Girls' Vocational High School opened in 1911.
Beginning in 1914, the junior high school was created from Forster Elementary School seventh and eighth grades.
By 1924, Somerville had three junior high schools.
In 1929, the Somerville Latin School was torn down to build the East Wing. The West Wing was built. The Central Wing, which was the old English High, was remodeled. The Gym Building was erected.
By 1983, all three junior high schools were closed. Ninth grade moved to Somerville High School. Somerville Technical Trade High School merged with Somerville High School.
In 1988, a construction project makes it a comprehensive high school.