Duplantier is a surname. Notable people with the surname include:
Adrian G. Duplantier (1929–2007), American jurist Armand Duplantier (1753–1827), French cavalry officer in the American Revolutionary War Joe Duplantier (born 1976), French-American musician Jon Duplantier (born 1994), American baseball player Mario Duplantier (born 1981), French-American musician, brother of Joe