The diocese was established in 1926, as the Diocese of Waikato, with Cecil Arthur Cherrington being the first bishop. In 2010, the name of the diocese was changed to the Diocese of Waikato and Taranaki. This reflects the structure of the diocese, with two bishoprics and two co-presiding bishops.
The seat of the Bishop of Taranaki is at the Taranaki Cathedral Church of St Mary. The incumbent Bishop of Taranaki is Philip Richardson (who has also been the archbishop of the New Zealand dioceses since 1 May 2013).