What is now the Parish House was built on another site on the property in the 1950's and transferred to the present site when the church was built. It served as the first residence for the priest, Fr Noel Mackay, parish priest of St Jude's Scoresby, when the church bought it in 1973 when the area of Rowville was part
of St Jude's parish.
St Simon's school was opened in 1982 with just over 100 children. The children first attended at St Jude's while the school was built that year and opened by Archbishop Little on 2 July. The second stage of the school was built in 1984.
A chapel / Community Centre was built and opened on 12 September 1985, and now serves as the Parish Hall.
St Simon's was established as a parish in its own right in January 1988 with Fr Les Tomlinson as the first parish priest. Five years later a church was built and blessed and opened by Archbishop Little on 13th November 1993. Sr Aileen was appointed as a Pastoral Associate.