The first five Principals of St Joseph’s were Christian Brothers.
They were…
| Brother Bernard Murphy | 1956-1961 |
| Brother Victor Larkin | 1962-1967 |
| Brother Donald Robertson | 1968-1973 |
| Brother Brian Saward | 1974-1979 |
| Brother Peter Fogarty | 1980-1983 |
They were followed by the following lay Principals
| Mr Peter Kenny | 1984-2001 |
| Mr Daniel McMahon | 2002-2008 |
| Mr Clem Welch | 2009-2016 |
| Mr Nicholas Lynch | 2017-2019 |
| Mr Kort Goodman | 2020-2023 |
Mr Jim Brennan is the current St Joseph’s College Principal