William Kerr may refer to:
- William Kerr, 1st Earl of Lothian (1605-1675)
- Sir William Kerr, 3rd Baronet (d. 1716), Member of Parliament for Scotland
- William Kerr (MP) (d 1741), MP for Aberdeen Burghs and Dysart Burghs
- Sir William Kerr, 4th Baronet (d. 1741)
- Sir William Kerr, 6th Baronet (d. 1755)
- William Kerr, 3rd Marquess of Lothian (ca 1690-1767)
- William Kerr, 4th Marquess of Lothian (1710-1775), also a Member of Parliament
- William Kerr (gardener) (d 1814), collector of plants in East Asia
- William Kerr, 6th Marquess of Lothian (1763-1824)
- William Johnson Kerr (1787-1845), a political figure in Upper Canada
- William Kerr (mayor) (1809–1853), mayor of Pittsburgh, Pennsylvania
- William G. Kerr (d after 1858), a former mayor of Hamilton, Ontario, Canada
- William Kerr (journalist) (1812-1859), Scottish-Australian journalist
- William Alexander Kerr (1831-1919), Scottish recipient of the Victoria Cross
- William Kerr (Canadian politician) (1836-1906), Canadian politician
- William Kerr (architect), (1836-1911) Irish-American architect
- William Munro Kerr (1876–1959), British admiral
- William Kerr (poet)
- William Kerr (baseball), co-owner of the Pittsburgh Pirates baseball team
- William Mark Kerr, film editor
