Treu is a surname. Notable people with the surname include:
Abdias Treu (1597–1669), German mathematician and academic Adam Treu (born 1974), American football player Blair Treu (born 1957), American film director Catharina Treu (1743–1811), German painter Georg Treu (1843-1921), German classical archaeologist and curator Kurt Treu (1928–1991), German classical philologist Paul Treu (born 1971), South African rugby union player and coach Philipp Treu (born 2000), German association football player Tiziano Treu (born 1939), Italian politician and academic Wolfgang Treu (politician) (died 1540), Austrian politician Wolfgang Treu (cinematographer) (1930-2018), German cinematographer
See also Trieu, Vietnamese surname