Barnstable County	001	Barnstable	1685	One of three original counties created in the Plymouth Colony	After its county seat of Barnstable, which is named after the English town of Barnstaple	215,888	396 sq mi
(1,026 km2)	State map highlighting Barnstable County
Berkshire County	003	Pittsfield	1761	From part of Hampshire County. Government abolished in 2000.[4]	For the English county of Berkshire	131,219	931 sq mi
(2,411 km2)	State map highlighting Berkshire County
Bristol County	005	Taunton	1685	One of three original counties created in the Plymouth Colony	For its original county seat of Bristol, Massachusetts, which is named for the English port city of Bristol . when the Town of Bristol joined Rhode Island, the name of the county was kept	548,285	556 sq mi
(1,440 km2)	State map highlighting Bristol County
Dukes County	007	Edgartown	1695	From Martha's Vineyard and the Elizabeth Islands, which had been part of Dukes County, New York until Massachusetts gained it in 1691	Formerly a part of Dukes County, New York until 1691, the land at one time was literally the possession of the dukes of York	16,535	104 sq mi
(269 km2)	State map highlighting Dukes County
Essex County	009	Salem and Lawrence	1643	One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1999.[4]	For the English county of Essex	743,159	498 sq mi
(1,290 km2)	State map highlighting Essex County
Franklin County	011	Greenfield	1811	From part of Hampshire County. Government abolished in 1997.[4]	For Benjamin Franklin (1706.1790), early American scientist, diplomat, and politician	71,372	702 sq mi
(1,818 km2)	State map highlighting Franklin County
Hampden County	013	Springfield	1812	From part of Hampshire County. Government abolished in 1998.[4]	John Hampden (1595.1643), the famous 17th century English parliamentarian	463,490	618 sq mi
(1,601 km2)	State map highlighting Hampden County
Hampshire County	015	Northampton	1662	From unorganized territory in the western part of the Massachusetts Bay Colony. Government abolished 1999.[4]	For the English county of Hampshire	158,080	529 sq mi
(1,370 km2)	State map highlighting Hampshire County
Middlesex County	017	Cambridge and Lowell	1643	One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1997.[4]	For the English county of Middlesex	1,503,085	824 sq mi
(2,134 km2)	State map highlighting Middlesex County
Nantucket County	019	Nantucket	1695	From Nantucket Island which had been part of Dukes County, New York until Massachusetts gained it in 1691.	The Town of Nantucket, itself derived from a Wampanoag word meaning "place of peace"	10,172	48 sq mi
(124 km2)	State map highlighting Nantucket County
Norfolk County	021	Dedham	1793	From part of Suffolk County.	For the English county of Norfolk	670,850	400 sq mi
(1,036 km2)	State map highlighting Norfolk County
Plymouth County	023	Plymouth and Brockton	1685	One of three original counties created in the Plymouth Colony.	For its seat of Plymouth, which is named for the English port city of Plymouth	494,919	661 sq mi
(1,712 km2)	State map highlighting Plymouth County
Suffolk County	025	Boston	1643	One of four original counties created in the Massachusetts Bay Colony. Government abolished in 1999.[4]	For the English county of Suffolk	722,023	58 sq mi
(150 km2)	State map highlighting Suffolk County
Worcester County	027	Worcester	1731	From parts of Hampshire County, Middlesex County and Suffolk County. Government abolished in 1998.[4]	For its county seat of Worcester, which is named in honor of the English city of Worcester and the English Civil War Battle of Worcester in 1651, a Parliamentarian victory	798,552	1,513 sq mi
(3,919 km2)	State map highlighting Worcester County