Rt Rev Jonathan Goodall, the Anglican Bishop of Ebbsfleet is stepping down from his role to seek "full communion with the Roman Catholic Church".
Bishop Jonathan has served in the role for eight years.
The Bishop of Ebbsfleet isn't part of a geographical diocese but provides oversight to parishes who do not accept the ordination of women priests.
Bishop Jonathan said: "I have arrived at the decision to step down as Bishop of Ebbsfleet, in order to be received into full communion with the Roman Catholic Church, only after a long period of prayer, which has been among the most testing periods of my life.
"Life in the communion of the Church of England has shaped and nourished my discipleship as a Catholic Christian for many decades. This is where I first received - and for half my life have ministered, as priest and bishop - the sacramental grace of Christian life and faith. I shall always treasure this and be thankful for it. I trust you all to believe that I have made my decision as a way of saying yes to God's present call and invitation, and not of saying no to what I have known and experienced in the Church of England, to which I owe such a deep debt."
His resignation has been accepted, "with regret", by the Archbishop of Canterbury.
Justin Welby said: "I am deeply grateful to Bishop Jonathan for his ministry and many years of faithful service.
"My prayers are with him and Sarah, both for his future ministry and for the direction in which they are being called in their continuing journey of dedicated service to Christ."
The archbishop also confirmed that a new process of consultation will begin to determine what happens to the role. Parishes affected will be included in that consultation.