William Hancock was born in Lisburn. He was educated at Dungannon and at Trinity College, Dublin. He attained a Doctorate in Laws, was called to the Bar in 1844, and became Queen's Counsel in 1880. He was Professor of Political Economy at Queen's College, Belfast, from 1849 to 1851, and he served as secretary on many Royal Commissions. He was President of the Statistical Society and published many pamphlets and reports.