The Roman Catholic Diocese of Aba takes its name from the major commercial city of Aba in Abia State. Aba Diocese was created from Umuahia Diocese on April 2, 1990. Its first diocesan bishop, Most Rev Dr. Vincent Valentine Ezeonyia, CSSp, was installed on 2 July 1990 at Christ the King Church; he was ordained Bishop 1 July 1990 at Mater Dei Cathedral in Umuahia. At the time the Catholic Diocese of Aba was created, there were 24 Parishes, 33 indigenous priests including those born and bred in Aba, many Religious men and women and a Catholic population of 227,225. The bulk of the Catholic population was concentrated in Aba Urban and its immediate environs. Dr. Ezeonyia died in 2015. The Catholic Diocese of Aba has recorded some striking progress since its inception in July, 1990 when His Lordship, Most Rev. Dr. Vincent Valentine Ezeonyia, C.S.Sp., began to pilot the administrative reins. The diocese has now 144 priests. She has now 59 parishes; the Diocese equally has a handsome number of her sons in the seminaries, and good number of her daughters in the convents. As the Diocese focuses on deepening the faith, it also focuses on improving the lot of the masses. The Bishop has built many secondary schools and numerous primary schools. The Diocese has a hospital and some Health Centres/Maternities. The Diocese is committed to improving and developing her schools, the hospital and health centers so that they can render the best of services to humanity. During the Great Jubilee Year 2000 of the coming of our Lord Jesus Christ, the Diocese celebrated the 10th Anniversary of her Creation. In this Jubilee year celebration the Bishop of the Diocese Most Rev. Dr. Vincent Valentine Ezeonyia. C.S.Sp, the Clergy and lay Faithful decided to hold a diocesan synod, a "Synod for True Christian Identity". This Synod of the Catholic Diocese of Aba came at a favourable time, a time when the Church calls her sons and daughters for a sober reflection, a time of grace, repentance, renewal, forgiveness, reconciliation, healing and thanksgiving. The synod sessions were held in 2001.
He was a Reverend Monsignor in Owerri Archdiocese and a Professor at Catholic Institute of West Africa when, on December 27, 2019, the Holy Father, Pope Francis, appointed him the new Bishop of Aba Diocese.
Other priest of this diocese who became bishop
Fortunatus Nwachukwu, appointed nuncio and titular archbishop in 2012