Currently working as Archdeacon of Buckingham she becomes the 36th Bishop of Sherborne and the ninth in modern times.
The Bishop of Sherborne works in the Diocese of Salisbury with responsibility mainly for parishes in Dorset.
She holds a BA from the University of Bristol and trained for the ministry at Trinity College, Bristol.
After being ordained as a priest in 1996 she went on to become Priest-in-Charge of St Paul's, Maidstone in the Diocese of Canterbury.
She has also worked as Honorary Canon of Canterbury Cathedral and has been a member of the Church of England General Synod for twelve years.
Her interests include travel and walking, the coast and Celtic spirituality. She enjoys days out with friends and an occasional visit to a good restaurant to sample the taster menu.
She said: "It has been a real privilege to serve the church in Buckinghamshire and work in the Diocese of Oxford. I now look forward to getting to know the people and places of Dorset, an area I have loved since childhood holidays."
Bishop of Salisbury, Rt Revd Nicholas Holtam said: "Karen has experience and brings gifts to help us with Renewing Hope: Pray, Serve, Grow.
"I think St Aldhelm would be pleased with her appointment, the first woman to the See of Sherborne which he founded.
"She emerged as the right person for this post from a company of excellent men and women considered equally.
"The Anglo-Saxon Church included women in authority as well as men, like St Cuthberga of Wimborne and St Edith of Wilton. Karen's appointment is good news for Salisbury and for the Church of England."