The Archdiocese of Onitsha () is a Latin Church archdiocese of the Catholic Church located in Anambra State. It encompasses the towns of Onitsha, Ogidi, Nkpor, Nnobi, Ojoto, Oba, Nkwelle Ezunaka, Umuoji, and Umudioka and Abatete.
The Archdiocese of Onitsha is the largest diocese in Nigeria by population, encompassing 196 parishes that serve around 1.3 million Catholics, in addition to hundreds of Catholic schools, hospitals and charities. The archdiocese also operates All Hallows Seminary in Onitsha. The archbishop is also the metropolitan of the larger Ecclesiastical Province of Onitsha.
Trinitas Newspaper is the digital news outlet of the archdiocese and includes a website, social media channels, and a weekly e-newsletter.
Bishop Joseph Shanahan was appointed the first Apostolic Prefect of what was then the Apostolic Prefecture of the Lower Niger in 1889 and the Apostolic Vicar of the Apostolic Vicariate of Southern Nigeria in 1920. Francis Cardinal Arinze became the first indigenous archbishop of the diocese. On 28 November 2001, Valerian Okeke was appointed Coadjutor archbishop of Onitsha by Pope John Paul II. He was consecrated the archbishop of the diocese on 9 February 2002 by Archbishop Osvaldo Padilla.
The ordinary of the Archdiocese of Onitsha is an archbishop whose cathedral is the Cathedral Basilica of the Most Holy Trinity in Onitsha. The archdiocese is the metropolitan see of the ecclesiastical province of Onitsha, which includes the following suffragan dioceses:
The ecclesiastical province includes all of Anambra State, Enugu State, and Ebonyi State. As such, the metropolitan archbishop possesses certain limited authority over the suffragan sees of the province (see ).
The Catholic Mission was established in Nigeria on 5 December 1885 with the advent of the missionaries of the Holy Ghost Fathers when they came to Onitsha. They include the religious mainly from France, Ireland and AlsaceâÂÂLorraine. On 25 July 1889, Onitsha was erected as an Apostolic Prefecture of the Lower Niger. It was formed from the larger Apostolic Vicariate of Benin Coast.
On 16 April 1920, the Prefecture was promoted as the Apostolic Vicariate of Southern Nigeria. On 9 July 1934, the Vicariate was renamed from Southern Nigeria to Apostolic Vicariate of Onitsha-Owerri and later on 12 February 1948, as the Vicariate of Onitsha.
On 18 April 1950, the Vicariate was promoted to an archdiocese together with the archdioceses of Lagos and Kaduna. Its cathedral was granted a minor basilica in 2007.
Blesseds