William Bayles (1 November 1820 – 8 October 1903), was a mayor of colonial Melbourne, Australia.

In 1864 he was elected to the Victorian Legislative Assembly for Villiers and Heytesbury, and was Commissioner of Trade and Customs in the short-lived Sladen ministry from May to July 1868.

After 1880 he retired from politics, but continued to called upon for his financial skills, as in 1886 when he served as liquidator of the South Suburban Gas Company.

[1] Bayles married, in 1854, Isabel, third daughter of Arthur Buist, of Macquarie River, Tasmania; they had at least seven children.

[2] He suffered a stroke in 1901 and died on 8 October 1903 at his home in Toorak.