27 July – Jens Olsen, clockmaker, locksmith and astromechanic, constructor of the World Clock in Copenhagen City Hall (d. 1945)
In addition to the tower clock, the City Hall also houses Jens Olsen's World Clock.
Mary-Kate Olsen | Jimmy Olsen | Jens Stoltenberg | Ashley Olsen | Gregory Olsen | Jens-Peter Herold | Jens Galschiøt | Jens Frahm | Olsen Gang | Olsen | Mary-Kate and Ashley Olsen | Jens Voigt | Jens Eriksen | Jens Ulltveit-Moe | Jens Munk | Jens Mouris | Jens Lehmann | Jens Juel | Jens Christian Grøndahl | William Olsen | Scott Olsen | Paul E. Olsen | Ola Dybwad-Olsen | Merlin Olsen | Jimmy Olsen (wrestler) | Jens Staubrand | Jens Peter Jacobsen | Jens Johansson | Gary Olsen | Walter Jens |