Dempster is a surname. Notable people with the surname include:
Arthur Jeffrey Dempster (1886–1950), Canadian-American physicist who discovered the 235U uranium isotope Arthur P. Dempster (1929–2026), American mathematical statistician and academic Barry Dempster (1952–2025), Canadian poet, novelist and editor Carol Dempster, American actress Charles Edward Dempster (1839–1907), Western Australian politician Charlotte Louisa Hawkins Dempster (1835–1913), British writer and folklorist Dallas Dempster, Australian businessman Edith Pretty (née Dempster) (1883–1942), English landowner who donated the Sutton Hoo treasure Edward Dempster (fl. 1667–1669), buccaneer who raided the Spanish alongside Henry Morgan Eric Dempster, New Zealand cricketer Everett Dempster, American geneticist George Dempster (lawyer), Scottish lawyer and MP George Roby Dempster, U.S. businessman and politician, founder of Dempster Brothers, Inc. Graham Dempster, Australian rules football player Hugh Dempster, British actor Jocky Dempster, Scottish footballer John Dempster (Medal of Honor), American Civil War sailor John Dempster (footballer), English footballer Leeann Dempster, chief executive of Hibernian F.C. Mary Dempster (born 1955), Canadian volleyball player Nigel Dempster, British journalist, author and broadcaster Quentin Dempster, Australian journalist Rebecca Dempster (born 1991), Scottish footballer Roland T. Dempster, Liberian writer Ryan Dempster, Canadian-born American baseball player Sean Dempster, Australian rules football player Stephen Dempster, Canadian religious scholar Stewie Dempster, New Zealand cricketer Stuart Dempster, American musician Thomas Dempster, Scottish scholar and historian Walter Dempster, Philippine drag queen and World War II sex slave