Fairfield County	001	Bridgeport	1666	original county	From the hundreds of acres of salt marsh that bordered the coast.	916,829	626 sq mi
(1,621 km2)	State map highlighting Fairfield County
Hartford County	003	Hartford	1666	original county	After the county of Hertfordshire in the UK	894,014	736 sq mi
(1,906 km2)	State map highlighting Hartford County
Litchfield County	005	Litchfield	1751	From parts of Fairfield, Hartford and New Haven Counties	City of Lichfield in the UK	189,927	920 sq mi
(2,383 km2)	State map highlighting Litchfield County
Middlesex County	007	Middletown	1785	From parts of Hartford and New London Counties	Former county of Middlesex in the UK	165,676	369 sq mi
(956 km2)	State map highlighting Middlesex County
New Haven County	009	New Haven	1666	original county	After New Haven Colony, founded as a haven in which Puritans could be free from persecution.	862,477	606 sq mi
(1,570 km2)	State map highlighting New Haven County
New London County	011	New London	1666	original county	After London, UK	274,055	666 sq mi
(1,725 km2)	State map highlighting New London County
Tolland County	013	Rockville	1785	From parts of Hartford and Windham Counties	Hamlet of Tolland, Somerset, UK	152,691	410 sq mi
(1,062 km2)	State map highlighting Tolland County
Windham County	015	Willimantic and Putnam	1726	From parts of Hartford and New London Counties	After Windham (now Wineham) in Sussex, England	118,428	513 sq mi
(1,329 km2)	State map highlighting Windham County