Davi Keith McCallum, Jr. (born September 19, 1933) is a prolific Scottish actor and the son of concertmaster violinist David McCallum, Sr.. He is best known for his role as Illya Kuryakin, a Russian-born secret agent, on the popular 1960s television series The Man from U.N.C.L.E., and Ducky Mallard on the series NCIS.