William D'Arcy may refer to:
Bill D'Arcy (William Theodore D'Arcy, born 1939), Queensland politician, accused and convicted of sexual abuse of children William Knox D'Arcy (1849–1917), furthered British interests in developing Persian (Iranian) oil William Alexander D'Arcy (1863–1940), cricketer from New Zealand
See also Sir William Darcy (c. 1460–1540), Anglo-Irish statesman William Darcy, a fictional character from The Lizzie Bennet Diaries, the 2012 web series