Lori was ordained by Cardinal William Baum on May 14, 1977 for the Archdiocese of Washington. After ordination he served as a parochial vicar at St. Joseph Parish in Largo, MD from 1977 until 1982. He earned a doctoral degree from The Catholic University of America in 1982 and served as a theological advisor to Cardinal James Hickey from 1982 until 2000. He also served as the director of ecumenical affairs for the Archdiocese from 1982–1986 and as Cardinal Hickey's priest–secretary from 1983 until 1994. In 1994, Lori became the chancellor, vicar general, and moderator of the curia.
In March 2001, he was appointed the Bishop of Bridgeport. As Bishop of Bridgeport, Lori launched new initiatives in support of catholic education, vocations, Catholic Charities, pastoral services, and other ministries, while improving financial stewardship. He also worked collaboratively with the laity to increase participation and foster lay leadership throughout the Diocese of Bridgeport. While serving in Bridgeport, Lori fought against releasing the names of diocesan priests who were being sued for sexual abuse, part of the Sexual abuse scandal in Bridgeport diocese. The Supreme Court ruled against Lori and the diocese. In 2002, Lori participated in writing the Dallas Charter. The initial draft applied to clerics, which includes bishops, priests, and deacons. The revised draft mentioned only priests and deacons, thus removing bishops from its purview. When questioned why, he is reported as saying the drafting committee "decided we would limit it to priests and deacons, as the disciplining of bishops is beyond the purview of this document. 'Cleric' would cover all three, so we decided not to use the word "cleric.'"
Archbishop of Baltimore
On March 20, 2012 Lori was appointed Archbishop of Baltimore by Pope Benedict XVI and he assumed that role upon installation May 16, 2012. In January 2019, Lori instituted an initiative for reporting allegations against any bishop in the Archdiocese of Baltimore. The policy was drafted by the archdiocesan Independent Review Board. As metropolitan archbishop, Lori was appointed apostolic administrator of the Roman Catholic Diocese of Wheeling-Charleston, following the retirement of Michael J. Bransfield, and headed an investigation into allegations that Bransfield had engaged in sexual harassment and engaged in inappropriate financial transactions. In June, 2019, the Washington Post obtained copies of the first draft of that report, as well as the final report that was sent to the Holy See. The names of several cardinals and bishops who had received payments from Bransfield were omitted in the final version, including that of Lori himself. When this news became public, Lori returned $7,500 to the diocese of Wheeling, West Virginia and asked that it be given to Catholic Charities. Other bishops followed his example. Lori admitted to the Baltimore Sun newspaper that he was responsible for removing the names of the cash recipients from the report, stating later “looking back on this in hindsight, I would say that judgment call was a mistake.”
