Constant is a surname. Notable people with the surname include:
Benjamin Constant (1767–1830), Swiss-born thinker, writer and French politicianBenjamin Constant (Brazil) (1836–1891), Brazilian military man and political thinkerDavid Constant (born 1941), international cricket umpireEdward Constant II (born c. 1942), American historianEmmanuel Constant (bishop) (1928–2009), Roman Catholic Haitian bishopEmmanuel Constant (born 1956), founder of FRAPHJean-Joseph Benjamin-Constant, (1845 – 1902), French painterMarius Constant (1925–2004), Romanian-born French composerPaul-Henri-Benjamin d'Estournelles de Constant (1852–1924), French diplomat and politicianPete Constant (born 1963), American politicianKevin Constant (born 1987), Guinean footballer