In a land area of 4,104 square kilometers, the diocesan territory covers Nagasaki prefecture.
In the diocesan territory, the population is 1,377,780 at the end of 2016. Most of them are ethnic Japanese. There are also 10,979 non-Japanese people according to the Immigration Bureau of Japan.
The territory also has many languages/dialects.
The origins of the Diocese of Nagasaki date to1866 when Bishop Bernard-Thadée Petitjean, M.E.P. was appointed to head the Vicariate Apostolic of Japan, which had been entrusted to the Paris Foreign Mission Society. In 1876, when the Vicariate Apostolic of Japan was divided into Northern and Southern Apostolic Vicariates, Nagasaki became part of the Southern Vicariate Apostolic, which had jurisdiction over the Kyushu, Chugoku, and Kinki regions. In 1888, when the Central Japan Vicariate Apostolic was established, the three regions of Shikoku, Chugoku, and Kinki were committed to it, and on June 15, 1891 the Diocese of Nagasaki was founded with the jurisdiction of all of Kyushu.
On July 16, 1927, the Diocese of Nagasaki became the first diocese under a Japanese ordinary, and, except for Nagasaki Prefecture, the rest of Kyushu was entrusted to the Diocese of Fukuoka and the Prefecture Apostolic of Kagoshima. Father Kyunosuke Hayasaka was appointed ordinary and in the same year became the first Japanese to be consecrated bishop. With the resignation of Bishop Hayasaka in 1937, Father Aijiro Yamaguchi became the ordinary and was ordained bishop. On May 4, 1959, the Diocese of Nagasaki was elevated to the rank of Archdiocese, and Bishop Yamaguchi was appointed the first Archbishop of Nagasaki.
With the resignation of Bishop Yamaguchi, Bishop Asajiro Satowaki of Kagoshima was appointed to succeed him on Dec. 19, 1968. He was installed as Archbishop of Nagasaki the following March 16.
On Nov. 10, 1977, Father Hisajiro Matsunaga was appointed auxiliary bishop. He was consecrated bishop on Feb. 5 of the following year. On Jan. 15, 1991, Bishop Matsunaga was installed as Bishop of Fukuoka.
On June 30, 1979, Archbishop Satowaki was created the third Japanese Cardinal.
On Feb. 8, 1990, Cardinal Satowaki resigned as archbishop and Bishop Kaname Shimamoto, Bishop of Urawa, was appointed his successor. He was installed on May 8 of the same year.
Sulpician Father Mitsuaki Takami, appointed auxiliary bishop of Nagasaki by Pope John Paul II on Feb. 7, 2002, was ordained Bishop in Nagasaki at the Cathedral on April 29.
Archbishop Shimamoto died Aug. 31, 2002. On October 17, 2003, Pope John Paul II appointed Auxiliary Bishop Takami as the archbishop of Nagasaki. Archbishop-elect Takami was installed in the see on Dec. 14, 2003. (Catholic Bishops' Conference of Japan, 2010)
Airplanes, railways, buses and ships are modes of transportation in the area.
Throughout Japan, literacy is 99 percent according to Central Intelligence Agency, USA, in 2010.