List of Famous people with last name Janssen

Walter Janssen was a German film actor and director. He appeared in more than 160 films between 1917 and 1970.

Johannes Adrianus "Jan" Janssen is a Dutch former professional cyclist (1962–1972). He was world champion and winner of the Tour de France and the Vuelta a España, the first Dutch rider to win either. He rode the Tour de France eight times and finished all but the first time. He won seven stages and wore the yellow jersey for two days. He was easily spotted in the peloton because of his blond hair and his glasses.

Paul Adriaan Jan, Baron Janssen was a Belgian physician. He was the founder of Janssen Pharmaceutica, a pharmaceutical company with over 20,000 employees which is now a subsidiary of Johnson & Johnson.

Zacharias Janssen ; also Zacharias Jansen or Sacharias Jansen; 1585 – pre-1632) was a Dutch spectacle-maker who lived most of his life in Middelburg. He is associated with the invention of the first optical telescope and/or the first truly compound microscope, but these claims may be fabrications put forward by his son.