St. Charles West opened its doors in September 1976 to 300 sophomores. During the first year physical education teachers taught in the cafeteria because the gymnasium was not completed until May 1977. Each year a class was added so that 1009 students were enrolled in grades 10-12 in 1978-79. The first graduation was held in the gymnasium in June 1979. With the addition of the ninth grade class in 1981 the school changed from a 10-12 high school to a 9-12 high school. In October 2003, ground was broken for the 17 million dollar renovation project. The project created a new practice gym, cafeteria, library space and rearranged the classrooms from the PODs to a more modern classroom arrangement. Currently there are 650 students enrolled for the 2023-24 school year.