Sir William Sullivan KCMG (8 December 1891 – 17 March 1967), in later life known as Bill Sullivan, was a New Zealand politician of the National Party.
He was born in Inglewood in 1891 to Irish parents Samuel John Sullivan and Sarah Maria (née Acton). Sullivan received his education in Inglewood and Stratford. He was a Taranaki rugby representative. He served in World War I in the New Zealand Expeditionary Force (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 1925–1938, the Harbour Board Chairman 1923–1926 and on the Council for almost 26 years.
Sullivan was one of three candidates in the 1931 election in the Tauranga electorate. He was a member of the United Party, but Charles MacMillan was the official candidate of the United-Reform Coalition, hence Sullivan stood as an Independent. He was defeated by MacMillan. Sullivan represented the Bay of Plenty electorate from a 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 appointed Knight Commander of the Order of St Michael and St George (KCMG) in the 1957 Birthday Honours.