Mata Hari (born Margaretha Geertruida Zelle, August 7, 1876, in Leeuwarden, Friesland), infamous dancer, courtesan; executed as a spy in France, October 1917
Joost Klein (born November 10, 1997 in Leeuwarden, Friesland), Dutch musician, rapper, singer and former Youtuber
Wilhelm von Knyphausen (1716–1800), general from Hesse-Cassel; fought in the American Revolutionary War, during which he led Hessian mercenaries on behalf of the British Empire
Tjalling Koopmans (1910–1985), Dutch American mathematician and economist; Nobel Prize Laureate in Economic Sciences
Anna-Marie Lampe, Playboy magazine (US edition) 40th anniversary Playmate/Playmate of the Month for January 1994; Playboy magazine (Dutch edition) Playmate of the year for 1995
Theodor Mommsen (1817–1903), received the Nobel Prize in Literature in 1902; German politician, member of the Prussian and German parliaments
Hans Momsen (1735–1811), North Frisian farmer, layman mathematician and astronomer
F. W. Matthiessen (1835-1918) Born in Altona, Denmark, Descendant of Matthias Petersen (Matthias der Gluckliche), co-founder of Matthiessen and Hegeler Zinc Works in LaSalle, IL (USA), Founder of Westclox (now General Time), Philanthropist, Matthiessen State Park Deer Park, IL (USA)
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Hark Olufs (1708–1754), sailor from Amrum; was enslaved by Algerian pirates; eventually became Commander in Chief of the Bey of Constantine's cavalry