Thomas Duncan

Thomas Duncan may refer to:
 * Thomas Duncan (general) (1819–1887), United States Army general during the Civil War
 * Thomas Duncan (Canadian politician) (died 1910), politician in Manitoba, Canada
 * Thomas Duncan (painter) (1807–1845), Scottish portraitist and historical painter
 * Thomas Duncan (American politician) (1893–1959), Milwaukee Socialist senator and representative
 * Thomas Young Duncan (1836–1914), New Zealand Liberal Party politician
 * Thomas William Duncan (1905–1987), US writer
 * Thomas Eric Duncan (1972–2014), first person to die of Ebola in the United States
 * Tommy Duncan (1911–1967), American musician
 * Tommy Duncan (footballer) (born 1936), Scottish footballer and manager