Gerretsen, Gerrets and Gerretse are Dutch patronymic surnames. Notable people with this name include:
Boris Gerrets (1948–2020), Dutch-born film director Chas Gerretsen (born 1943), Dutch photojournalist John Gerretsen (born 1942), Canadian politician Mark Gerretsen (born 1975), Canadian politician Wolphert Gerretse van Kouwenhoven (1579–1662), Dutch settler in New Netherland known by his patronym Gerretse
See also Gerritsen Gerritszoon