The son of a book-binder and milliner, William Yarrington came to Australia with his parents as a child, and spent much of his early life in Sydney. He was ordained as a deacon of the Church of England in 1870, and as a priest in 1872, and subsequently served in the N.S.W. country centres of Balranald, Yass, and West Maitland, and then metropolitan Burwood (in Sydney), where he retired in 1909. During his early years in the ministry, Yarrington also completed studies at the University of Sydney, obtaining a B.A. in 1877, a M.A. in 1880, and a L.L.B. in 1887. In addition to his poetical works, Yarrington published a number of sermons and theological pamphlets. He was a botanical collector of some standing, and he was also a founding member of the Royal Australian Historical Society, serving as its president in 1903 and 1910.
In 1859, Yarrington was awarded the W. C. Wentworth Prize for Poetry for his poem 'Cook, Meditating on Australia's Future', which he read at the opening of the Great Hall at the University of Sydney, on 18 July, 1859.