The son of Michael Stancliffe, former Dean of Winchester, who was himself ordained at Salisbury Cathedral, Stancliffe was born in 1942 in Devizes, Wiltshire, where his father was curate of St James' Southbroom, later serving at Ramsbury and Cirencester before becoming Chaplain to Westminster School.
While at university, Stancliffe abandoned thoughts of a musical career in favour of ordination and instead went to theological training at Cuddesdon College in October 1965.