Irish and Scots origin and also appears as Duffy or O' Duffy in Ireland. The Irish Gaelic form is 'O Dubhthaigh' which means "descendant of Dubhthach", a byname derived from "dubh", meaning black. The name was borne by a 6th Century saint who was Archbishop of Armagh.
The Scots Gaelic form is "Mac Dhuibhshithe", son of Dubhshith, a personal name composed of the element "dubh", with the same meaning as the Irish version in the modern idiom the variants include Duffie, Dowey, Dowie, Do(v)ey, Duthy, McDuffie, McFee. The name is common in Angus.
Seven people of this name are recorded in Dunblane from 1598, and one Alexander Duthie was a planter in Jamaica in 1769. The first recorded spelling of the family name is shown to be that of Marjory Duthe, which was dated 1492, in Holme, Orkney, during the reign of King James 1V of Scotland, 1488 - 1513. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.
The name is also found in France and Amsterdam D'uty, Duthe, Duthy, Du Thy. Catherine-Rosalie Gerard Duthé (1748–1830, alt: Duthe or Du The) was a celebrated French courtesan. A companion of French kings and European nobility, she has been called "the first officially recorded dumb blonde." Duthé was an often requested subject for portraits, including partial and full nudes, many of which still exist in museums and private collections. After quitting a French convent, Duthé became the mistress of wealthy English financier George Wyndham, 3rd Earl of Egremont (1751–1837).