Rt Rev Graham James, who is currently the Church of England's longest serving bishop, said he and his wife will move to Cornwall.
Bishop Graham said: "It's been a privilege and honour to serve as Bishop of Norwich for almost 19 years, and Julie and I will find it hard to leave.
"We are returning to Cornwall (to Truro) but the Diocese of Norwich and her people will always have a big place in our hearts."
"Please pray for us as we prepare for this new chapter in our lives, as well as for those who will be responsible for the appointment of my successor."
A service planned for Norwich Cathedral on Sunday 25th November 2018 will mark the end of Bishop Graham's public ministry.
The Bishop of Thetford Rt Rev Alan Winton said: "We are fortunate to have been served by a man of such immense gifts and such a tremendous capacity for work and friendship.
"There are few corners of the life of the diocese where he has not made an impact over almost two decades, and so many people whose lives he has touched and influenced for the better."
National guidelines shall dictate the appointment of a new Bishop of Norwich. Diocesan officials said that process will start "in due course".
The Dean of Norwich, Very Revd Jane Hedges said: "Bishop Graham's departure from this diocese is going to leave an enormous gap in all of our lives.
"It has been a tremendous privilege as Dean to work alongside him for these past four years and to witness his ministry amongst such a wide range of people.
"All who have experienced his preaching and teaching will know that he is an outstandingly gifted speaker, his words always striking just the right note in both a profound and often amusing way."
Bishop Graham celebrated four decades of priesthood in September 2016. His responsibilities have included being the Church of England's spokesman on media issues.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.