Publisher. Son of Thomas Nelson (1780 - 1861), he joined his father's publishing firm in 1835. Nelson travelled the world selling books. When their Hope Park Works burned to the ground in 1878, William and his brother quickly restored production on a new site provided by the city authorities. They were so grateful that they donated fine pillars which were sited at the east end of Melville Drive in Edinburgh's Meadows.
Nelson restored Salisbury Green, a late 18th century house which he bought in 1860. It is located next to Edinburgh's Holyrood Park and is now a student residence, part of the University of Edinburgh's Pollock Halls complex. Nelson was also involved in the restoration of the Old Parliament Hall in Parliament Square.
He is buried in Edinburgh's Grange Cemetery, next to his father and brother, Thomas (1822 - 92).