The Whanganui Collegiate School Old Boys & Girls Association came into being on 12 July 1889. Mr Walter Empson, then Headmaster, was elected as first President.

Over the years the Association has offered considerable financial and moral support to the School.

The first major effort was to fund the building of the Chapel in 1912 to commemorate all that Headmaster Walter Empson had done during his 25 years at the School. In 1986 the Chapel was extended – the funding again being led by the Old Boys, as it has been for later development projects. Several WCSOBGA trust funds exist for special purposes, including bursaries.