Demby is a surname. Notable people with the surname include:
Albert Joe Demby (1934-2021), Sierra Leonean politician and Vice President Constance Demby (1939–2021), US musician, composer, artist Edward Thomas Demby (1869–1957), US author and religious figure Jack Demby (1888–1963), one of the names used by Austrian football athlete Jamil Demby (born 1996), American football player William Demby (1922–2013), American writer
See also Denby (disambiguation)