Molenaar is a Dutch surname deriving from the Dutch word for "miller".
Molenaar is the surname of:
Beau Molenaar (b. 1985), a Dutch football goalkeeper
Cees Molenaar (1928-1979), founder of the football club AZ
Dee Molenaar (b. 1918), an American mountaineer, author and artist
Frans Molenaar (b. 1940), a Dutch fashion designer
Hillie Molenaar (b. 1945), a Dutch documentary film director
Jan Molenaar (1958-2009), a New Zealand gunman of the 2009 Napier shootings
Keje Molenaar (b. 1958), a Dutch footballer
Klaas Molenaar (1921-1996), founder of the football club AZ
Marjolijn Molenaar (b. 1983), a Dutch cricketer
Robert Molenaar (b. 1969), a Dutch footballer
Tim Molenaar (b. 1981), a New Zealand rugby player
Willem Molenaar (b. 1945), a Dutch cricket umpire