Wynne was born in London, but his family emigrated to Australia when he was a child. He educated at Melbourne Church of England Grammar School and enrolled in an articled clerk's course at the University of Melbourne and was admitted as an attorney in July 1874. He married Mary Jane Robertson, née Smith, a widow with two children in November 1886. She died in 1889 and in February 1896 he married Annie Dudgeon, née Samuel, a widow with three children.[1]
In 1910, Wynne acquired Nerrin Nerrin, a 7,927-acre (3,208 ha) property near Streatham, Victoria. He ran merino sheep, raised Thoroughbred horses and created a wildlife sanctuary. He also had pastoral interests elsewhere in Victoria and in Queensland.[1]
A supporter of the war effort, in 1917 Wynne offered £500 to the first member of the proposed Sportsman's Battalion to win the Victoria Cross.[3]
Wynne suffered a series of strokes late in life and died at Nerrin Nerrin on 12 May 1934, aged 83. He was survived by the daughter of his first marriage.[1]