St Pius X College started in 1937 as Christian Brothers Chatswood, initially going to the Intermediate level.

The first Leaving Certificate class graduated in 1949.

In the early 1950s the school was renamed St Pius X College and the first of many building programs commenced.

The College expanded its curriculum and other activities along with its facilities throughout the 1960s, 70s and 80s.

A major improvement in the 1990's was the development of Oxford Falls as an educational complex. Named the Treacy Complex (comprising the Treacy Education Centre-1992 and the Christian Brothers’ Centre-2010), the facility comprises a variety of sports fields (Chaplin Ovals #1 & 2 and Walsh Ovals #1 & 2) and venues as well as a number of meeting places and classrooms.

In the late 1990s the College undertook extensive renovations and rebuilding to make the academic facilities some of the most effective in NSW.