Demaine or de Maine is a surname. Notable people with the surname include:
Erik Demaine (born 1981), Canadian computer scientist, son of Martin
Martin Demaine (born 1942), American artist & computer scientist, father of Erik
Mike Demaine (born 1948), Australian footballer (Australian rules)
Paul A. D. de Maine (1924–1999), American computer scientist
Robert deMaine (born 1969), American cellist