Seeley was ordained in the Church of England: made a deacon at Michaelmas 1978 (24 September), by David Tustin, Bishop of Grimsby, at St Paul's Ashby,[4] and as a priest the Michaelmas following (30 September 1979), by Simon Phipps, Bishop of Lincoln, at Lincoln Cathedral.
[1] In 1980, Seeley returned to the United States where he was a curate at the Church of the Epiphany and assistant director of Trinity Church, Manhattan, New York City (1980–1985) and then executive director of the Thompson Center, an ecumenical lay and clergy education programme in St Louis, Missouri (1985–1990).
In September 2006, he was appointed Principal of Westcott House, Cambridge, a theological college in the Liberal Catholic tradition of the Church of England.
[16] In November 2023, he was one of 44 Church of England bishops who signed an open letter supporting the use of the Prayers of Love and Faith (i.e. blessings for same-sex couples) and called for "Guidance being issued without delay that includes the removal of all restrictions on clergy entering same-sex civil marriages, and on bishops ordaining and licensing such clergy".
He married Jutta Brueck who was his curate at Christ Church with St Luke's, Isle of Dogs on 23 January 1999; she is also a priest.