Sir William Austin Zeal KCMG (5 December 1830 – 11 March 1912) was an Australian railway engineer and politician, Senator for Victoria in the Parliament of Australia. Zeal was born at Westbury, Wiltshire, England, the son of Thomas Zeal, a wine merchant, and Ann, nee Greenland. Educated privately, Zeal obtained his diploma as a surveyor and engineer, and came to Melbourne in 1852. Employed as an engineer in charge of railway construction by private contractors, Zeal was also employed in the government service for some years. In 1864, he was elected to Victorian Legislative Assembly as one of the three members for the seat of Castlemaine.