St. Paul's Roman Catholic School Division was formally established in 1911 at the request of Catholic parents who desired that their children receive a Catholic faith-based education. From a modest beginning of 69 students in the basement of St. Paul's Church, the school division now encompasses over 17,000 students in seven high schools, 43 elementary schools, two associate schools, and a high school tutorial program.
Following school amalgamations in 2006, the school division grew to include Biggar, Humboldt and communities surrounding Saskatoon. Since that time, it has maintained its legal name of St. Paul's RCSSD # 20 and has also adopted a common name of Greater Saskatoon Catholic Schools (GSCS).
Catholic school divisions were created in the cities of Martensville in 2010 and Warman in 2014. Each of these divisions then amalgamated with GSCS shortly after their formation.