Founded in 1924, the school was established initially in Bann House on the banks of the River Bann, adjacent to the main road bridge of the time. In 1962 the school moved to a new, purpose-built site, on the Killicomaine Road. The school previously had a preparatory department until its closure in 2006.
Portadown College has seen many major changes in education. Originally established as a fee-paying voluntary grammar school, it embraced the changes of the The Education (Northern Ireland) Act 1947 and, subsequently, has made a major contribution to the present ‘two-tier’ system of secondary education in the Craigavon area.