| Christopher S. Koper | American sociologist | |
| Suvi Koponen | Finnish model | 1988 |
| Sheldon Kopp | American psychotherapist | 1929–1999 |
| Ted Koppel | television journalist | 1940 |
| Bonnie Koppell | American rabbi | |
| Janusz Korczak | Polish physician and writer | 1878–1942 |
| Michael Korda | British writer | 1933 |
| Snježana Kordić | Croatian linguist | 1964 |
| Harmony Korine | American film director and sc… | 1973 |
| Gordon Korman | Canadian American children's … | 1963 |
| János Kornai | Hungarian economist | 1928 |
| Jack Kornfield | American writer | 1945 |
| Sergei Korolev | Soviet rocket engineer and sp… | 1906–1966 |
| Beryl Korot | American artist | 1945 |
| Edward M. Korry | American politician | 1922–2003 |
| Alan Charles Kors | American academic | 1943 |
| Ruslana Koršunova | fashion model | 1987–2008 |
| David Korten | writer, sustainability advoca… | 1937 |
| Janusz Korwin-Mikke | polish politician | 1942 |
| Kristin Kory | | |
| Alfred Korzybski | Polish scientist and philosop… | 1879–1950 |
| K-os | Canadian rapper, singer, song… | 1972 |
| Epicharmus of Kos | ancient Greek dramatist and p… | -524–-435 BC |
| Damodar Dharmananda Kosambi | Indian mathematician | 1907–1966 |
| Nathalie Kosciusko-Morizet | French politician | 1973 |
| Tadeusz Kościuszko | Polish and American military … | 1746–1817 |
| Jerzy Kosiński | Novelist | 1933–1991 |
| Ronnie Kosloff | | |
| Zoya Kosmodemyanskaya | Soviet resistance member of W… | 1923–1941 |
| Simisola Kosoko | Nigerian singer and songwriter | 1988 |
| Stephen Kosslyn | American psychologist | 1948 |
| Lajos Kossuth | Hungarian politician | 1802–1894 |
| Elizabeth Kostova | American writer | 1964 |
| Joseph Kosuth | American conceptual artist | 1945 |
| Tivadar Csontváry Kosztka | painter from Hungary | 1853–1919 |
| Philip Kotler | American marketing author, co… | 1931 |
| Steven Kotler | American journalist | 1967 |
| Alan Kotok | American computer scientist | 1941–2006 |
| John P. Kotter | author of The heart of Change | 1947 |
| August von Kotzebue | German dramatist | 1761–1819 |
| Menachem Mendel of Kotzk | Polish rabbi | 1787–1859 |
| Sandy Koufax | American baseball player | 1935 |
| Jannis Kounellis | Greek painter, sculptor and p… | 1936–2017 |
| Ernie Kovacs | American comedian, actor, and… | 1919–1962 |
| Gergely Kovács | archbishop of Alba Iulia | 1968 |
| Mary Robinette Kowal | American writer and puppeteer | 1969 |
| Ben Kowalewicz | musician | 1975 |
| Killer Kowalski | Canadian professional wrestler | 1926–2008 |
| Koxinga | Chinese military leader | 1624–1662 |
| James Ah Koy | Fijian politician | 1936 |
| Sidiq Koya | Fijian politician | 1923–1993 |
| Shane L. Koyczan | | |
| Alexandre Koyré | French philosopher | 1892–1964 |
| Rich Koz | American actor and comedian | 1952 |
| Ivo Kozarčanin | Croatian writer | 1911–1941 |
| Ivan Kozhedub | Soviet aviator, thrice hero o… | 1920–1991 |
| Alex Kozinski | American judge | 1950 |
| Jonathan Kozol | American activist and educator | 1936 |
| Konrad Krajewski | Roman Catholic cardinal | 1963 |
| David Krakauer | scientist | 1967 |
| Jon Krakauer | American outdoors writer and … | 1954 |
| Jeffrey Kramer | American actor and producer | 1945 |
| Gene Kranz | NASA Flight Director and mana… | 1933 |
| Walerian Krasiński | historian | 1795–1855 |
| Zygmunt Krasiński | One of Poland's three nationa… | 1812–1859 |
| Lee Krasner | American artist | 1908–1984 |
| Vadim Krasnoselsky | politician | 1970 |
| László Krasznahorkai | Hungarian novelist and screen… | 1954 |
| Joseph Martin Kraus | German composer | 1756–1792 |
| Karl Kraus | Czech playwright and publicist | 1874–1936 |
| Lawrence M. Krauss | American physicist | 1954 |
| Nicole Krauss | American novelist | 1974 |
| Charles Krauthammer | American journalist | 1950–2018 |
| Ed Krebs | American photographer and mus… | 1951 |
| Peter Kreeft | American philosopher | 1937 |
| Mullah Krekar | Islamic scholar | 1956 |
| Lorin Krenn | | |
| Jayne Ann Krentz | American novelist | 1948 |
| Kristin Kreuk | Canadian actress | 1982 |
| John Kricfalusi | Canadian animator | 1955 |
| Lou Krieger | | |
| Robby Krieger | American rock guitarist and s… | 1946 |
| Tim Kring | | |
| Saul Kripke | American philosopher | 1940 |
| S. M. Krishna | Indian politician | 1932 |
| Kalki Krishnamurthy | writer | 1899–1954 |
| Jiddu Krishnamurti | Indian spiritual philosopher | 1895–1986 |
| U.G. Krishnamurti | Indian philosopher | 1918–2007 |
| Kariamanickam Srinivasa Krishnan | Indian physicist | 1898–1961 |
| Marta Kristen | Norwegian actress | 1945 |
| Julia Kristeva | Bulgarian-French philosopher,… | 1941 |
| Nicholas D. Kristof | journalist, author, columnist | 1959 |
| Ágota Kristóf | Hungarian Swiss writer | 1935–2011 |
| Kris Kristofferson | American country music singer… | 1936 |
| Irving Kristol | American columnist, journalis… | 1920–2009 |
| William Kristol | American writer | 1952 |
| Zdravko Krivokapić | Montenegrin politician and pr… | 1958 |
| Miroslav Krleža | Croatian writer | 1893–1981 |
| Greg Kroah-Hartman | Linux kernel developer | |
| Ray Kroc | American businessman | 1902–1984 |
