The Diocese of Youngstown consists of six counties: Mahoning, Trumbull, Columbiana, Stark, Portage, and Ashtabula.

However, unlike other parts of the future American Midwest, there were no attempts to found Catholic missions in Ohio.

In 1763, after the end of the French and Indian War, Ohio Country became part of the British Province of Quebec, forbidden from settlement by American colonists.

Instead, a visiting priest from Painesville would intermittently undertake a day's journey by horse to Ashtabula over secondary rural roads.

In 1858, the diocese established the St. Joseph Mission in Ashtabula and assigned Father Charles Coquelle as its resident priest.

Masses were celebrated in private homes until 1860, when parishioners constructed a small wooden frame church.

The purchase of an additional five acres in 1877 allowed construction of St. Joseph's two-story brick secondary school, staffed by the Sisters of the Humility of Mary.

Towards the turn of the century, a large influx of Italian Catholics prompted the formation of a third church in Ashtabula.

[10] A strong advocate of interfaith communication, Malone was elected as the first Catholic leader of the Ohio Council of Churches.

[11] The post of bishop remained vacant for almost two years, with Monsignor Robert J. Siffrin serving as diocesan administrator.

In November 2020, Pope Francis named Reverend David J. Bonnar of Pittsburgh as the sixth bishop of Youngstown.

The United States Conference of Catholic Bishops (USCCB) established a comprehensive set of procedures in June 2002 called the Charter for the Protection of Children and Young People.

The document mandates permanent national and diocesan offices to oversee adherence to the guidelines for accountability, prevention, reconciliation, and healing in response to reports of abuse by clergy and other Catholic employees and volunteers.

Serving as a baseball coach at John F. Kennedy High School, he abused teenage boys under the pretense of providing athletic massages.

[19] In October 2018, the Diocese of Youngstown released a list of over 30 priests and other clergy with credible accusations of sexual abuse of minors.

[20] Reverend Denis G. Bouchard, former pastor of Queen of the Holy Rosary Parish in Vienna, sued the diocese and three individuals who had accused him of child sexual abuse in October 2019.

[23] In April 2023, the Maryland District Attorney released an investigative report on sexual abuse by priests in that state.

The report related the history of Reverend John Hammer, who served in Youngstown and East Liverpool during the early 1980s.

As of 2023, the system has the following campuses:[26] Walsh University – North Canton The Diocese of Youngstown for 78 years published a print newspaper, The Catholic Exponent.