| William Black | |
| Order: | 4th |
| Office: | Mayor of Saint John, New Brunswick |
| Predecessor: | John Robinson |
| Successor: | Lauchlan Donaldson |
| Term Start: | 1828 |
| Term End: | 1829 |
| Order2: | 6th |
| Office2: | Mayor of Saint John, New Brunswick |
| Predecessor2: | Lauchlan Donaldson |
| Successor2: | John McNeil Wilmot |
| Term Start2: | 1832 |
| Term End2: | 1833 |
| Order3: | 12th |
| Office3: | Mayor of Saint John, New Brunswick |
| Predecessor3: | Robert F. Hazen |
| Successor3: | Lauchlan Donaldson |
| Term Start3: | 1840 |
| Term End3: | 1843 |
| Birth Place: | Aberdeen, Scotland |
William Black (1771 – 18 June 1866) was a Canadian shipper, merchant, and office-holder born in Aberdeen, Scotland.
Black grew up and was educated in Scotland. He immigrated to New Brunswick in 1798 to work with his brother John, an established shipping and timber export merchant. By 1808, he was managing their timber trade in Saint John while his brother opened a new office in Halifax, Nova Scotia. In a few years, they had the largest business enterprises in British North America. They both married daughters of Christopher Billopp, a leading an influential businessman and member of the Legislative Council of New Brunswick.
Black was appointed to the Council in 1817 by George Stracey Smyth, the Lieutenant Governor. He eventually achieved the position of president of the council.
During his time as acting governor of the colony of New Brunswick in 1829 to 1831, they had named the small village of Blackville after him.