The earliest Catholic presence in what is now the State of Georgia began with the arrival of Spanish missionaries in the 16th century. For many years the Franciscans maintained a network of mission stations which stretched from St. Augustine to the Savannah River.

The arrival of the British brought an end to the period of Spanish presence. No Catholics were permitted in the new colony of Georgia. After the Revolutionary War small groups moved into the area of Locust Grove, near Augusta, and to Savannah, where the church of St. John the Baptist was established.

Savannah belonged first to the Diocese of Baltimore, and later to the Diocese of Charleston. In 1850 the numbers of Catholics had grown, and a new Diocese of Savannah was formed, taking in the entire State of Georgia and a large part of the State of Florida.

Immigration from Europe and the movement of population from the northern United States southward swelled the Catholic population over the years. In January 1937, the name of the diocese was changed to the Diocese of Savannah-Atlanta. It was re-designated with its original name on November 8, 1956, when the northern part of the state became a separate diocese. The Diocese was re-named Diocese of Savannah-Atlanta in 1937, with a cathedral in each city. In 1956 the division became permanent, with Atlanta (later an Archdiocese) taking the northern part of the State, Savannah taking the southern half. The Cathedral of St. John the Baptist, dedicated in 1876, is the seat of the Diocese of Savannah. Today the Diocese includes 90 counties of the southern part of Georgia. There are 73,649 Catholics.