The diocese was founded in around 679 by St Theodore of Canterbury at Worcester to minister to the kingdom of the Hwicce, one of the many Anglo Saxon petty-kingdoms of that time. The original borders of the diocese are believed to be based on those of that ancient kingdom.Della Hooke, The Kingdom of the Hwicce (1985), pp.12-13
On its creation the diocese included what is now southern and western Warwickshire (an area known as Felden). In 1837 the north and east of Warwickshire (Arden) which formed the archdeaconry of Coventry in the then Diocese of Lichfield and Coventry was transferred to the diocese of Worcester. In 1905 an area in northern Warwickshire was split off as the Diocese of Birmingham, and in 1918 an area approximating to the rest of Warwickshire was made the Diocese of Coventry.