A suffragan bishop is a bishop subordinate to a metropolitan bishop or diocesan bishop. They may be assigned to an area which does not have a cathedral of its own.
In the Anglican churches, the term applies to a bishop who is an assistant to a diocesan bishop. For example, the Bishop of Jarrow is a suffragan to the diocesan Bishop of Durham.
Suffragan bishops in the Anglican Communion are nearly identical in their role to auxiliary bishops in the Roman Catholic Church.
English diocesan bishops were commonly assisted by bishops who had been consecrated to sees which were in partibus infidelium (titular sees that had in most cases been conquered by Muslims) before the English Reformation. The separation of the English Church from Rome meant that this was no longer possible. The Suffragan Bishops Act 1534 allowed for the creation of new sees to allow these assistant bishops, who were named as suffragan. Before then, the term suffragan referred to diocesan bishops in relation to their metropolitan.
The concept of a suffragan bishop in the Church of England was legalised by the Suffragan Bishops Act 1534. The first bishops consecrated under that Act were Thomas Manning, Bishop of Ipswich and John Salisbury, Bishop of Thetford on 19 March 1536. The last Tudor suffragan bishop in post was John Sterne, Bishop of Colchester, who died in post in 1607/8. No more suffragans were appointed for more than 250 years, until the consecration of Henry Mackenzie as Bishop of Nottingham on 2 February 1870. At that point, the sees of suffragans were still limited to the 26 towns named in the 1534 Act; the Suffragans Nomination Act 1888 allowed the creation of new suffragan sees besides the 26 so named. The appointment of bishops suffragan became much more common thereafter.