Constant is a surname. Notable people with the surname include:

• Benjamin Constant (1767–1830), Swiss-born thinker, writer and French politician
• Benjamin Constant (Brazil) (1836–1891), Brazilian military man and political thinker
• David Constant (born 1941), English cricket umpire
• Edward Constant II (born c. 1942), American historian
• Emmanuel Constant (bishop) (1928–2009), Roman Catholic Haitian bishop
• Emmanuel Constant (born 1956), Haitian criminal
• Eugen Constant (1890–1975), Romanian writer and trade unionist
• Eugène Constant (1901–1970), French rower
• F. Woodbridge Constant (1904–1988), American physicist
• Jean-Joseph Benjamin-Constant, (1845–1902), French painter
• Kevin Constant (born 1987), Guinean footballer
• Marius Constant (1925–2004), Romanian-born French composer
• Paul-Henri-Benjamin d'Estournelles de Constant (1852–1924), French diplomat and politician
• Pete Constant (born 1963), American politician

• Constance (name)
• Constant (given name)
• Constant-Désiré
• Benjamin-Constant
• Benoît-Constant
• Saint-Constant (disambiguation)