David or Dave Duncan may refer to:
Arts and entertainment David Duncan (writer) (1913–1999), American screenwriter and novelist; wrote the screenplay for The Time Machine David Douglas Duncan (1916–2018), American photographer Dave Duncan (writer) (1933–2018), Scottish-Canadian fantasy and science fiction writer David James Duncan (born 1952), American novelist, essayist, and fly-fisher
Sports Davie Duncan (1921–1991), Scottish footballer Dave Duncan (baseball) (born 1945), American Major League Baseball player and pitching coach David Duncan (footballer) (born 1963), Ghanaian football player and manager David Duncan (ski cross) (born 1982), Canadian ski cross racer
Others David Duncan (minister) (1789–1829), Scottish Presbyterian minister David Duncan (politician) (1830–1886), British merchant and Liberal politician David Duncan (diplomat) (1923–2007), British diplomat David F. Duncan (born 1947), American epidemiologist and expert on drug abuse David Ewing Duncan (born 1958), American journalist David Duncan (accountant) (born 1960), United States government's star witness in the Arthur Andersen trial David Duncan (vintner) (born 1965), American vintner and entrepreneur
See also David Duncan Main (1856–1934), British doctor