The Archdiocese of Hartford comprises the counties of Hartford, Litchfield and New Haven in Connecticut and includes approximately 700,000 Catholics. Over 500 priests minister within the Archdiocese, serving 216 parishes as well as other apostolates. The priests are assisted by almost 300 deacons.

Hartford was established as a diocese on November 28, 1843 and created as an archdiocese on August 6, 1953. It includes the following towns and cities:

Ansonia, Avon, Bantam, Barkhamsted, Beacon Falls, Berlin, Bethany, Bethlehem, Bloomfield, Branford, Bridgewater, Bristol, Broad Brook, Canaan, Canton, Cheshire, Colebrook, Collinsville, Cornwall, Cornwall Bridge, Derby, Devon, East Berlin, East Granby, East Hartford, East Hartland, East Haven, East Windsor, Elmwood, Enfield, Falls Village, Farmington, Forestville, Glastonbury, Goshen, Granby, Guilford, Hamden, Hartford, Hartland, Harwinton, Kensington, Kent, Lakeville, Litchfield, Madison, Manchester, Marlborough, Meriden, Middlebury, Milford, Mount Carmel, Naugatuck, New Britain, New Hartford, New Haven, New Milford, New Preston, Newington, Norfolk, North Brnaford, North Canaan, North Haven, Northfield, Northford, Oakville, Orange, Oxford, Plainville, Plantsville, Pleasant Valley, Plymouth, Poquonock, Prospect, Rocky Hill, Roxbury, Salisbury, Seymour, Sharon, Simsbury, South Glastonbury, South Meriden, South Windsor, Southbury, Southington, Suffield, Tariffville, Terryville, Thomaston, Torrington, Union City, Unionville, Wallingford, Warren, Washington Depot, Waterbury, Watertown, West Hartford, West Haven, West Simsbury, Wethersfield, Winchester, Windsor, Windsor Locks, Winsted, Wolcott, Woodbridge, Woodbury, Woodmont, Yalesville.