Dejean is a surname. Notable people with the surname include:
Louis Dejean (1872–1954), French sculptor and engraver
Mike DeJean (born 1970), American baseball player
Jean François Aimé Dejean (1749–1824), French army officer and minister of state in the service of the First French Republic and the First French Empire
Jean-Luc Déjean (1921–2006), French writer
Philippe DeJean (1736–c.1809), judge in Fort Detroit until he was captured during the American Revolution
Pierre Charles Dejean (1807–1872), French general and politician
Pierre François Marie Auguste Dejean (1780–1845), French entomologist
Jorge Tomás Dejean (1998), Argentinian capo master, odontologist, Juanchila's roommate.
