Karl Janssen (29 May 1855 — 2 December 1927) was a German sculptor working in the Baroque revival tradition; he was born and died in Düsseldorf.
In 1897, together with Josef Tüshaus [de], whom he had known from their days at the Akademie, he was commissioned to produce a sculptured group for the visit to the city by Kaiser Wilhelm, on the theme of Father Rhine and his Daughters.
The result so pleased Düsseldorfers that Janssen and Tüshaus were requested to cast a more durable version in bronze, for a city fountain.
The previous year (1896), he cast an equestrian statue of the Kaiser, which was destroyed in the Second World War.
Since 1893 he had been teaching as a professor, taking the chair of the late August Wittig [de], who had been his teacher.