William Sinclair

William Sinclair may refer to:

• William Sinclair, 1st Earl of Caithness (1410–1484), Scottish nobleman
• William Sinclair, 2nd Earl of Caithness (1459–1513), Scottish nobleman
• William Sinclair, 10th Earl of Caithness (1727–1779), Scottish nobleman

• William Pirrie Sinclair (1837–1900), MP for Antrim and Falkirk Burghs
• W. E. N. Sinclair (1873–1947), Canadian barrister, solicitor and politician
• William Henry Sinclair (1864–1902), Canadian politician in the Legislative Assembly of the Northwest Territories

• William Sinclair (bishop) (died 1337), bishop of Dunkeld
• William Sinclair (priest) (1804–1878), Scottish author and rector of Pulborough, Sussex
• William Sinclair (archdeacon of London) (1850–1917), Anglican priest and author
• William Sinclair (United Irishmen) (died 1830), Irish revolutionary

• William Sinclair (cricketer) (1846–1869), Australian cricketer
• William Sinclair (general) (1835–1905), US Army brigadier general
• William Sinclair (footballer) (born 1934), Scottish footballer
• William Sinclair (fur trader) (1790s–1868), chief factor of the Hudson's Bay Company
• William H. Sinclair (1838-1897) Businessman; Union Officer
• William John Sinclair (1877–1935), American geologist and paleontologist
• William Angus Sinclair (1905–1954), Scottish philosopher
• Will Sinclair, a character in Angel in My Pocket

• William Saint-Clair (disambiguation), "Saint-Clair" is a variant of "Sinclair"
• Sinclair (disambiguation)
• William (disambiguation)