 His first post after ordination was as a curate at Crowborough Parish Church.He then held incumbencies at St Paul, Hyson Green, Nottingham and St Ann with Emmanuel, in the same city before being appointed Archdeacon of Nottingham in 1978, his last post before elevation to the Episcopate.On 11 February 2017, Williamson was one of fourteen retired bishops to sign an open letter to the then-serving bishops of the Church of England.