Mrs Spence succeeds Sir Hugh Duberly, who retires in April after 14 years as Lord-Lieutenant of the county.
Julie Spence was Chief Constable of Cambridgeshire from 2005 to 2010. Since her retirement from the police, she has served as Chair of the Cambridge and Peterborough NHS Foundation Trust and as a Trustee of Ormiston Families which supports young people from disadvantaged communities. She lives in Cambridge with her husband, John.
Current Lord-Lieutenant Sir Hugh Duberly said: "I am delighted that Julie Spence has been appointed to succeed me as Lord-Lieutenant. She has a deep knowledge of the county and its people through her time as Chief Constable, and her present role as Chairman of the Cambridgeshire Mental Health Trust. I wish her well."
Cambridgeshire County Council Chairman Sebastian Kindersley added: "Mrs Spence has been a loyal servant of Cambridgeshire as Chief Constable and latterly with the NHS. I am delighted that service to the people of Cambridgeshire will continue. We welcome our new Lord-Lieutenant and offer many congratulations on her appointment."