Maertens is a surname. Notable people with the surname include:
Bert Maertens (born 1981), Belgian politician Birger Maertens (born 1980), Belgian footballer Bob Maertens (1930–2003), Belgian footballer and manager Erhard Maertens (1891–1945), German Vizeadmiral of the Kriegsmarine Freddy Maertens (born 1952), Belgian cyclist Grégoire Maertens (born 1924), Belgian Esperantist Mathieu Maertens (born 1995), Belgian footballer Rémy Maertens, Belgian tug of war competitor Willy Maertens (1893–1967), German actor