St. Mary's BNS, Maynooth was built in 1943 during World War II. It took pupils from 2nd to 6th – boys only.
In the late fifties it opened as a lay 'Secondary Top', which meant that pupils could continue right to Leaving Certificate. This continued until 1971.
In 1976 the school increased from five to sixteen classrooms to coincide with the rapid development of the town.
In recent years the school has further expanded to meet the needs of the community.