William Workman was born on May 1, 1807, in Ballymacash, County Antrim, Ireland.

He was a merchant, businessman, mayor of Montreal, and philanthropist. From 1827 to 1829, he worked for the Ordnance Survey of Ireland, and, in 1829, he moved to Canada with his family. He began to work for the newspapers, Canadian Courant and Montreal Advertiser. In 1830, he joined his brothers Benjamin and Thomas in Canada's largest tool and hardware wholesale business of John Frothingham. By 1836, the Workmans had become full partners, and William remained in the partnership until his retirement in 1859. In 1842, he built an impressive mansion in Montreal's Golden Square Mile, which he named "Mount Prospect". He was one of the founders of the Montreal City and District Savings Bank in 1846 and became the bank's first president, 1846-1862, and a director, 1861-1872. Workman was Mayor of Montreal from 1868 to 1871 and invested heavily in railways (Champlain and St. Lawrence railway), shipping (Canadian Ocean Steam Navigation Company), real estate, and charity. He helped establish the Montreal Protestant House of Industry and Refuge in 1864 and served as its president from 1874 to 1877. He was also president of the St. Patrick’s Society of Montreal.

In 1831, he married Elizabeth (Eliza) Bethell (1805–1885). He died on February 23, 1878, in Montreal, Quebec.