Historic figures: K
- John Keats (1795-1821) - 19th century Romantic poet
- James Keir Hardie (1856 - 1915) - politician, first leader of the Labour Party
- Sir William Thomson, Lord Kelvin (1824 - 1907) - Victorian physicist, mathematician
- John F Kennedy (1917 - 1963) - Cold War US president, assassinated
- John Maynard Keynes (1883 - 1946) - influential 20th century economist
- Khafra (Khephren) (c.2558 BC - c.2532 BC) - ancient Egyptian architect, model for the Sphinx
- Ayatollah Khomeini (1900-1989) - 20th century leader of Iran's Islamic revolution
- Nikita Khrushchev (1894-1971) - Cold War Soviet leader during the Cuban Missile Crisis
- Khufu (2609 BC - 2584 BC) - Egyptian pharaoh, built Great Pyramid at Giza
- Kilby and Noyce (1923-2005) - electrical engineers, invented the microchip
- Martin Luther King (1929 - 1968) - 20th century US civil rights leader, assassinated
- Rudyard Kipling (1865-1936) - 19th-20th century writer, Nobel prize winner
- Henry Kissinger (1923 - ) - 20th century US academic, politician, Nobel prize winner
- Lord Horatio Kitchener (1850 - 1916) - British world War One general, mobilised mass armies