On July 13, 2021, Pope Francis appointed John Iffert, a priest of the Diocese of Belleville, as bishop of Covington.

It includes the city of Covington and the following Kentucky counties: Boone, Kenton, Campbell, Gallatin, Carroll, Grant, Owen, Pendleton, Harrison, Bracken, Robertson, Mason, Fleming, and Lewis.

[3] Among the early missionaries was Stephen Badin who set out on foot for Kentucky on in 1793, sent by Bishop John Carroll of the Diocese of Baltimore.

For the next 14 years Badin traveled on foot, horseback and boat between widely scattered Catholic settlements in Kentucky and the Northwest Territory.

He appointed Reverend George Carrell, the president of Xavier University in Cincinnati, Ohio, as its first bishop.

In 1869, Reverend Augustus Toebbe of the Archdiocese of Cincinnati was appointed as the second bishop of Covington by Pope Pius IX.

[8] He opened a boys' orphanage in Cold Spring in 1870, erected a hospital in Lexington in 1874, and established a diocesan seminary in 1879.

[9] After Toebbe died in 1884, Pope Leo XIII named Monsignor Camillus Maes of the Diocese of Detroit as the next bishop of Covington.

At the time of his arrival, the diocese counted a Catholic population of 38,000 people, 42 parishes, and 38 priests[10] By the beginning of Maes' tenure as bishop, St. Mary's Cathedral had fallen into disrepair.

To replace Maes, Pope Benedict XV in 1915 named Reverend Ferdinand Brossart as the next bishop of Covington.

Pope Pius XI appointed Reverend Francis Howard that same year as bishop of Covington.

The next bishop of Covington was Monsignor William Mulloy of the Diocese of Fargo, named by Pope Pius XII in 1944.

During his tenure, Hughes was criticised for inviting pro-choice figures, such as US Representative Robert Drinan, S.J., and actress Marlo Thomas to speak at church-sponsored events,[16] and for saying Mass for gays and lesbians at Chicago in 1992.

John Paul II in 1996 named Auxiliary Bishop Robert Muench from the Archdiocese of New Orleans as Hughes' replacement in Covington.

The diocese acquired $40 million by liquidating real estate assets, including the Marydale Retreat Center in Erlanger, and other investments.

"[25]In 2009, local media reported that 243 victims of clergy sexual abuse in the diocese had received an average of $254,000 each, totaling approximately $79 million.

[27] In August 2019, Reverend David Glockner was arrested after being accused of inappropriately touching two high school girls who were volunteering in a construction project at a farm in Vanceburg.

[30] However, it was reported in November 2019 that 92 priests and brothers who served in the diocese were accused of sexual abuse by not just the Vatican, but also by prosecutors and in civil litigation since 1959.