William Byrnes (2 June 1809 – 25 October 1891) was an Australian politician.
He was born in Parramatta to James and Frances Byrnes; his father was a member of the New South Wales Corps.
He was an apprentice saddler before pioneering steam ferries on the Parramatta River with his brother James.
[1] Byrnes was a member of the New South Wales Legislative Council from August 1858 to May 1861 and from September 1861 until his death at Parramatta in October 1891.
[3] His nephew, Charles, James' youngest son was also a member of the Legislative Assembly between 1874 and 1882.