William Haines (South Australian politician)

William Haines (c. 1816 – 25 January 1866) was a politician in colonial South Australia.

Haines arrived in South Australia in 1838. He held a number of positions, including that of Mayor of Adelaide (1858-1859) and Member of the South Australian Legislative Council from 1861 until his death in 1866. As Mayor, he laid the foundation stone for the Albert Tower in Victoria Square. His business interests appear to have been varied. He was involved in gold mining activities in the Echunga Goldfields and also operated a brewery. He was also a partner in the mercantile firm of Elder, Stirling & Haines.