The Bishop of Ely is the ordinary of the Church of England Diocese of Ely in the Province of Canterbury. The diocese roughly covers the county of Cambridgeshire (with the exception of the Soke of Peterborough), together with a section of north-west Norfolk and has its episcopal see in the City of Ely, Isle of Ely in Cambridgeshire, where the seat is located at the Cathedral Church of the Holy Trinity. The diocesan bishops resided at the Bishop's Palace, Ely until 1941; they now reside in Bishop's House, the former cathedral deanery.
The roots of the Diocese of Ely are ancient and the area of Ely was part of the patrimony of Saint Etheldreda. Prior to the elevation of Ely Cathedral as the seat of the diocese, it existed as first as a convent of religious sisters and later as a monastery. It was led by first by an abbess and later by an abbot. The convent was founded in the city in 673. After St Etheldreda's death in 679 she was buried outside the church. Her remains were later translated inside, the foundress being commemorated as a great Anglican saint. The monastery, and much of the city of Ely, were destroyed in the Danish invasions that began in 869 or 870. A new Benedictine monastery was built and endowed on the site by Saint Athelwold, Bishop of Winchester, in 970, in a wave of monastic refoundations which also included Peterborough and Ramsey. In the Domesday Book in 1086, the Abbot of Ely is referenced as a landholder of Foxehola. The abbey became a cathedral in 1109, after a new Diocese of Ely was created out of land taken from the Diocese of Lincoln. From that time the line of bishops begins.