This surname is derived from the name of an ancestor. 'the son of Dolphin,' popularly Doven and Duffen. There need be no hesitation in accepting this origin. The personal name was common, and a corrupted form was inevitable; v. Dolphin.

Willelmus Duffane, 1379: Poll Tax of Yorkshire.

Nicholaus Duffane, 1379: ibid.

Since writing the above I find the point practically settled by the Lancashire Inquisitions (Lancashire and Cheshire Record Soc). A comparison of Ribchester names (1606) on., and Ribchester names (1609) on. Will serve to show that Robert Dolphin in the one case, and Robert Dewfine in the other, were one and the same person. There are several Dolphins in the present directory for Ribchester.

1759. Married — William Bruce and Margaret Duffin: St. George, Hanover Square.

1 = Duff (q.v.) + the Irish diminutive suff. -in.

2 an assimilated form of Dolphin, q.v.

Ó Duibhin Though found in Munster in mediaeval times, from the seventeenth century Duffin has been mainly found in east Ulster and Louth. SIF 59

There are early references to Ó Duibhin (bishop of Kildare 1148), O'Duffyne (Cork, 1311), O'Doghwyn (Co. Waterford, 1573) and O'Duffyn (Co. Cork, 1601) but from the middle of the seventeenth century the name Duffin, by that time already beginning to be deprived of its O, became closely associated with the Oriel country and the adjacent parts of Ulster. In the 1659 “census” it appears as a principal Irish surname in Co. Louth; in 1664 it was in the Co. Monaghan and Co. Armagh hearth money rolls; and in the same decade occurs also in those of Antrim and Tyrone; in 1689 we find it at Carlingford. By the end of the eighteenth century the location had moved more definitely to Antrim, particularly the Ballymena area. There have also been a number of Duffin families in Co. Wexford and Co. Waterford, deriving no doubt from the early Munstermen of the name referred to above; some of these, however, lost their identity by adopting Duff as a synonym, and that seems also to have happened to some extent in the case of the northern Duffins.

Duff, as an epithetic surname from dubh (black) has no distinct location. As the almost extinct O'Duff it is cognate with Devoy (see Irish Families p. 89). As MacDuff it is Scottish.

Ó Duibhin Though found in Munster in mediaeval times, from the seventeenth century Duffin has been mainly found in east Ulster and Louth. SIF 59

(Irish) The little person with a dark complexion; descendant of Dolphin or Dolfin (Delphian); grandson of Dubhfionn (black Fionn).