William Sotheby was born circa 1688 in England (England) to James Sotheby (1655-1720) and Anne Norris Robinson (c1659-1727) and died 7 February 1766 of unspecified causes. He married Elizabeth Sloane (c1725-?) 20 October 1750 .
Children
| Name | Birth | Death | Joined with |
| Elizabeth Sotheby (1751-1827) | |||
| Rose Sotheby (c1753-?) | |||
| Anne Sotheby (1754-?) | |||
| William Sotheby (1756-1833) | 9 November 1756 Essex, England, United Kingdom | 30 December 1833 | Mary Isted (1759-1834) |
| Thomas Sotheby (1758-1831) | 15 May 1758 | July 1831 | Sarah Anstey (c1762-c1802) Mary Anne Bourke (c1783-1830) |