Sir William Sullivan (1891 – 17 March 1967) was a New Zealand politician of the National Party.
He represented the Bay of Plenty electorate from the 1941 by-election after the death of Gordon Hultquist to 13 February 1957, when he resigned following the death of his son who ran the family construction business.
He was the Minister of Labour, Mines, Housing and the State Advances Corporation in the First National Government from 1949 to 1957, including the period of the 1951 Waterfront dispute.
He was born in Inglewood, and was a Taranaki rugby representative. He served in World War I in the NZEF and in World War II at Trentham Military Camp in New Zealand. He set up a construction company in the Bay of Plenty, and in Whakatane was Mayor 1925-28, the Harbour Board Chairman 1923-26 and on the Council for almost 26 years. He was made K.C.M.G. in 1957.