The Irish surname McDevitt is of patronymic origin. The name is an anglicized form of the Gaelic name Mac Daibhéid, a patronymic from the Gaelic equivalent of David. The personal name David is a Hebrew name meaning “beloved.” The name McDevitt is found throughout Ireland with high concentrations in the western province of Connaught, particularly counties Mayo and Galway. John Devitt arrived in Philadelphia from Ireland in 1811 and today there are approximately 7,000 bearers of the name in the United States.