In a land area of 15,020 square kilometers, the diocesan territory covers Osaka, Hyogo and Wakayama prefectures.
In the diocesan territory, the population is 15,333,735 at end of 2016. Most residents are ethnic Japanese. There are also 314,842 non-Japanese people, according to the Immigration Bureau of Japan.
On June 15, 1891, the vicariate apostolic of Central Japan was raised to the status of a diocese and constituted diocese of Osaka. The vicar apostolic, Monsignor Felix Nicolas Midon, M.E.P., was consecrated bishop. On Jan. 27, 1904, with the establishment of the prefecture apostolic of Shikoku, all of Shikoku was entrusted to Spanish Dominicans, and on May 4, 1923, with the establishment of the vicariate apostolic of Hiroshima, the five prefectures of Okayama, Hiroshima, Yamaguchi, Shimane, and Tottori were entrusted to German Jesuits.
On June 17, 1937, when the prefecture apostolic of Kyoto was established, the four prefectures of Kyoto, Nara, Mie, and Shiga were entrusted to the Maryknoll Fathers, and the present jurisdiction consisting of the Hyogo, Osaka, and Wakayama regions was established. In 1940, upon the resignation of Bishop Jean-Baptiste Castanier, M.E.P., Father Yoshigoro Taguchi was appointed to succeed him and was consecrated bishop on Dec. 14, 1941.
On June 24, 1969, the Osaka diocese was raised to the rank of archdiocese and Bishop Taguchi was appointed the first archbishop of Osaka.
On Feb. 5, 1970, Father Hisao Yasuda was appointed auxiliary bishop and was consecrated on March 21, the same year.
On March 3, 1973, Archbishop Taguchi was elevated to a cardinal. On Feb. 23, 1978, Cardinal Taguchi died, and on Nov. 15 of the same year Bishop Yasuda was appointed archbishop of Osaka.
Father Jun Ikenaga, S.J. was appointed coadjutor archbishop of Osaka on Nov. 2, 1995. He was consecrated bishop on March 20, 1996.
Archbishop Yasuda resigned on May 10, 1997, and Archbishop Ikenaga was installed on June 22, 1997.
Auxiliary Bishop Goro Matsuura was consecrated on July 17 of the same year. On August 20, 2014, Archbishop Ikenaga resigned and Bishop Manyo Maeda of Hiroshima was appointed archbishop of Osaka, who was installed on September 23. (Catholic Bishops' Conference of Japan)
Airplanes, railways, ships and buses connect the diocesan territory with the world.
Throughout Japan, literacy is 99 percent, according to the Central Intelligence Agency, US, report 2010.