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 and computer scientist, father of Erik Mike Demaine (1948–2013), Australian footballer (Australian rules) Paul A. D. de Maine (1924–1999), American computer scientist Robert deMaine (born 1969), American cellist William Demaine (1859–1939), Australian politician David Demaine (1942–2025), English footballer
See also Demaine, Saskatchewan, hamlet in Saskatchewan, Canada