Namesakes
Hall-of-Famers:
1 ice hockey
(ice hockey) Duncan "Mickey" MacKay 1952 
Nobel Prize Winners:
1 physics
(physics) Duncan Haldane 2016
Notable Actors and Actresses:
2 actors
Duncan Regehr 1952-
Robert Duncan McNeill 1964-
Notable Athletes:
1 cricket, 1 ice hockey, 1 rugby
(ice hockey) Duncan "Mickey" MacKay 1894-1940
(cricket) Hamish Rutherford (a.k.a. Duncan) 1989-
(rugby) Duncan Weir 1991-
Olympic Medalists:
3 gold, 2 silver, 1 gold/bronze, 1 gold/silver
(silver) Duncan Gillis 1912 hammer throw
(gold) Dunc Munro (a.k.a. Duncan) 1924 ice hockey
(gold) Duncan McNaughton 1932 high jump
(silver) Duncan White 1948 400 m hurdles
(gold/bronze) Duncan Goodhew 1980 swimming - 100 m breaststroke; swimming - 4x100 m medley relay
(gold/silver) Duncan Armstrong 1988 swimming - 200 m freestyle; swimming - 400 m freestyle
(gold) Duncan Keith 2010; 2014 ice hockey
Scottish Kings and Queens:
2 kings
King Donnchad I the Gracious (a.k.a. Duncan) 1034-1040
King Donnchad II (a.k.a. Duncan) 1094
Shakespearian Characters:
1 character
Duncan Macbeth
Title Characters:
1 book
(book) Duncan 1990 Duncan's bride