In response to the flood of returning WWII veterans, Principal F. Cyril James took over the site of former R.C.A.F. base (built in 1940-1941) at St-Jean, Quebec. The Sir William Dawson College, named for former McGill Principal Sir William Dawson, opened September 26, 1945.

All first year students in Science and Engineering as well as some second year students from these faculties attended the college. By 1947, the McGill student enrolment had reached just over 8,000 students in degree and diploma programs, more than doubled the enrolment a decade earlier. Dawson College played a crucial role in the Canadian post-war recovery effort, providing post-secondary education and support to veterans and their families.