Wahroonga Prep School and Knox Grammar School have had a long association with St. John’s Church. In years past the Knox Boarders would walk across to St. John’s for weekly worship. Today St. John’s Church is used for weekly worship with all children from PK to Year 6 every Tuesday from 8:30am to 9:00am. Parents, community and members of St. John’s congregation attend this weekly Chapel Service. Throughout the year Wahroonga Prep School holds special church services to celebrate Easter, Mothers Day, Fathers Day, Christmas and other important celebrations. These services are often held on a Thursday so that all Pre-Kindergarten children can attend. Every third Tuesday the congregation from St. John’s Church hosts a morning tea after the Wahroonga Prep Chapel Service.
There are three Chaplains associated with Wahroonga Prep School and Knox Grammar School. Rev Tim Robinson, Rev Peter Robinson and Pastor Louise lead the weekly Chapel Services in St. John’s Church.