| Sir William Gilbert | |
| Order: | Director New Zealand Security Intelligence Service |
| Term Start: | 28 November 1956 |
| Term End: | July 1976 |
| Successor: | Paul Molineaux |
| Birth Name: | Herbert Ellery Gilbert |
| Birth Date: | 20 July 1916 |
| Birth Place: | Wanganui, New Zealand |
| Death Place: | Silverstream, New Zealand |
| Spouse: | Patricia Caroline Anson Gilbert (née Farrer) |
| Alma Mater: | Royal Military College, Duntroon |
| Allegiance: | New Zealand |
| Branch: | New Zealand Army |
| Serviceyears: | 1935–1956 |
| Rank: | Brigadier |
| Commands: | 6th Field Regiment |
| Battles: | Second World War |
| Mawards: | Knight Commander of the Order of the British Empire Distinguished Service Order Mentioned in Despatches Bronze Star (United States) |
Sir William Herbert Ellery Gilbert, (born Herbert Ellery Gilbert; 20 July 1916 – 26 September 1987), was a New Zealand military leader and intelligence service director.
Gilbert was born in Wanganui on 20 July 1916. In 1953, he was awarded the Queen Elizabeth II Coronation Medal.[1] In 1956, he was tasked by Jack Marshall, then Minister of Justice, with setting up the New Zealand Security Service. Over 19 years, he served under seven Prime Ministers. He was appointed Knight Commander of the Order of the British Empire (KBE) in the 1976 Queen's Birthday Honours, just one month prior to his retirement.
He was born as Herbert Ellery Gilbert. At the Australian Royal Military College in Duntroon he was nicknamed Bill, and the name stuck. After his retirement, he changed his name by deed poll to William Herbert Ellery Gilbert.