He was the third son of John Barker, a merchant of Bildeston, Suffolk. He was educated at St John's College, Cambridge and trained for law at the Inner Temple.^[1]

He was the Member of Parliament for Colchester, Essex four times between 1597 and 1621.^[1][2]

He became a JP for Harwich in 1601 and Essex in 1607 (until 1617) and was made Serjeant-at-Law for Colchester in 1612. He died in at Monkwick in 1618.^[1]

He had married Margaret, the daughter of Robert Coke of Mileham, Suffolk; they had two sons and three daughters. he was succeeded by his eldest son Bestney.^[1]

• J.H. (1981). "Barker, Robert III (1563-1618), of Bildeston, Suff.; later of Monkwick, Essex.". In Hasler, P.W. (ed.). The History of Parliament: the House of Commons 1558-1603. Boydell and Brewer.
• Willis, Browne (1750). Notitia Parliamentaria, Part II: A Series or Lists of the Representatives in the several Parliaments held from the Reformation 1541, to the Restoration 1660 ... London. pp. 139, 140, 159, 170.