William Theakston was born on 24 April 1857, in Markham, York, Ontario, Canada as the son of Charles Theakston and Hannah Smith. He married Mary Adeline Lanktree on 6 February 1900, in Collingwood, Simcoe, Ontario, Canada. They were the parents of at least 2 sons and 2 daughters. He lived in Grey, Ontario, Canada for about 10 years. He died on 27 March 1932, in Ravenna, Blue Mountains, Grey, Ontario, Canada, at the age of 74, and was buried in Thornbury-Clarksburg Union Cemetery, Blue Mountains, Grey, Ontario, Canada.