The Catholic Historical Society of Western Pennsylvania considers itself the successor to the first Catholic historical society in the United States, the Ohio Valley Catholic Historical Society, founded in 1884 by Msgr. Andrew Arnold Lambing. Since its latest revival in 1984, the Society has hosted and facilitated a variety of publications, events, and initiatives to document, protect, and popularize the history of the Catholic Church in Western Pennsylvania. One of its primary activities is the publication of Gathered Fragments, an annual full-color historical journal.

The Society is listed under the Diocese of Pittsburgh in the Official Catholic Directory. Since 1993, it has been incorporated as a non-profit organization under Code Section 501(c)(3) of the Internal Revenue Code.