The Diocese of Duluth includes Aitkin, Carlton, Cass, Cook, Crow Wing, Itasca, Koochiching, Lake, Pine and St. Louis Counties.

[2] During the 17th and 18th centuries, French Catholic missionaries passed through the Duluth area accompanying voyageurs on their explorations of the Upper Great Lakes.

At the time of McGolrick's arrival in Duluth in January 1890, the new diocese contained 22 priests, 32 churches, ten stations, five parochial schools, and a Catholic population over 20,000.

[16] He organized five regional pastoral councils, encouraged charismatic services, and improved Catholic relations with Protestants and Jews.

Monsignor Dennis Schnurr of the Diocese of Sioux city was the next bishop of Duluth, named by John Paul II in 2001.

In June 2020, Pope Francis appointed Monsignor Michel Mulloy from the Diocese of Rapid City as the next bishop of Duluth.

However, before his consecration in October, the Diocese of Rapid City removed Mulloy from ministry, having receiving an allegation of sexually abusing a minor in the 1980s.

The plaintiff had alleged being sexually abused as a 15 year old altar boy by Reverend James Fitzgerald, a diocesan priest, in 1978.

It took this action after facing the Fitzgerald verdict, six other lawsuits and 12 additional claims stemming from child sexual abuse cases.

Despite the accusations in Guam, the diocese in 1981 had allowed Brouillard to move to Pine City and assist at the local parish.

[27] In May 2019, the Diocese of Duluth agreed to pay $40 million to 125 plaintiffs who were the alleged victims of sexual abuse by 37 diocesan priests.