Born: October 22, 1890, Caithness, United Kingdom
Died: June 15, 1970 (age 79 years), Twickenham, United Kingdom
Children: Robin Sinclair, 2nd Viscount Thurso, Angus Sinclair, Catherine Sinclair, and more
Grandchildren: John Thurso, Veronica Linklater, Baroness Linklater of Butterstone, Diana Lyle, and more
Spouse: Marigold Forbes (m. 1918)
Great grandchildren: Louisa Ticknor Beaumont Sinclair, Jody Peter Fergus North Sinclair, Mevagh Janet Sanson, and more
Date knighted: 1940