Deer is a surname. Notable people with the surname include:
Ada Deer (born 1935), Native American leaderBrian Deer (21st century), British investigative reporterGary Mule Deer (21st century), American comedianGene Deer (21st century), American blues guitaristGeorge Deer (1890-1974), British politicianJames Young Deer (died 1946), Native American film actorRob Deer (born 1960), American baseball playerLaurence Deer (born 1990), English digital marketing pioneer