Mahieu is both a surname and a given name. Notable people with the name include:
- Albert Mahieu (1860-1926), French politician.
- Jacques de Mahieu (1915–1990), French Argentine anthropologist and Peronist
- Jesse Mahieu (born 1978), Dutch field hockey player
- Thomas Mahieu, 16th-century French politician and bibliophile
- Mahieu de Gant, Flemish trouvère
- Mahieu le Juif, French trouvère