Demeter is a surname. Notable people with the surname include:
Christine Demeter (died 1973), murder victim Dimitrija Demeter (1811–1872), Croatian poet and playwright Don Demeter, American baseball player George Demeter, author of Demeter's Manual of Parliamentary Law and Procedure Peter Demeter, Christine Demeter's husband, convicted in her death Steve Demeter (1935–2013), American baseball player and scout