The Bishop of Huntingdon, the Right Reverend David Thomson, is to act as interim bishop for the Diocese of St Edmundsbury & Ipswich.
He will take charge until a permanent bishop for the diocese is selected to replace the Right Reverend Nigel Stock, who was invited by the Archbishop of Canterbury to become Bishop at Lambeth.
Bishop Stock will be part of Archbishop Justin Welby's senior team based in London from October.
In the meantime, Bishop Thomson will continue to serve as Bishop of Huntingdon, a role he has had since 2008.
He said: "It is a great privilege to be asked to work as a shepherd for Christ's people in the Diocese of St Edmundsbury & Ipswich as they wait for a new diocesan bishop.
"I pray that I will be able to help them to continue to grow in faith, deepen discipleship, and share richly the good things God has given us with the communities we serve."
Bishop Stock is leaving the Diocese of St Edmundsbury & Ipswich after being at the helm since 2007.
He said: "I am enormously grateful to Bishop David and the Diocese of Ely for this generous offer of ministry which will be very reassuring for the people of this diocese in the vacancy."