The Diocese of Ohio is part of the worldwide Anglican Communion represented in the United States by The Episcopal Church.

As settlers and missionaries moved westward after the Revolutionary War, they brought their faith traditions with them, including those of the newly formed Episcopal Church.

After years of fruitless petitions and through the hard work of missionaries and others, the General Convention of the Episcopal Church finally granted Ohio a separate diocese in 1818.

In December 1861 Bishop MacIlvaine was part of delegation sent to England by President Abraham Lincoln to assist in counteracting a hostile negative opinion which had arisen following "the Trent Affair."

Bishop Bedell had staunchly supported the Union in the Civil War, and, like McIlvaine, has been credited with keeping the Episcopal Church unified during this time, unlike many other denominations.

The Diocese of Ohio favored more evangelical expression of worship and theology, and Bishop Bedell moved its headquarters to Cleveland at its northeast corner, in the growing urban areas along Lake Erie.

Thomas Augustus Jaggar was then consecrated the first bishop of the new Episcopal Diocese of Southern Ohio, which had some parishes favoring more Anglo-catholic styles and established its headquarters in Cincinnati in the state's southwestern corner.