Delancey (also De Lancey and de Lancey) is a surname. Notable people with the name include:
James De Lancey, British colonial Governor of New York between 1753 and 1760
James De Lancey (disambiguation), other people of that name
Oliver De Lancey (disambiguation), multiple people
Etienne de Lancey (1663-1741), a French nobleman
William Howe De Lancey (1778-1815), Wellington's Chief of Staff at the Battle of Waterloo.
DeLancey W. Gill (1859–1940), American photographer
Scott DeLancey (born 1949), American linguist