The hamlet Hertonäs is mentioned in the sources back in the Middle Ages. The manor's current main buildning was originally erected as a fajance factory.
Later on the manor has vitnessed the dramatic destinies of the families Cronstedt and Bergbom. Viceadmiral Carl Olof Cronstedt, who was accused for treason, passed away with bad reputation here in Hertonäs manor in 1820. Almost a hundered years later the red guards stormed the main buildning and shot the owner, John Bergbom, at his breakfasttable.
Hertonäs manor has also been used as a scene for shooting many movies. Many wellknown Finnish movies from the 20th century are filmed in the surroundings of the manor.
Nowadays Hertonäs manor is owned by the society Svenska Odlingens Vänner i Helsinge, who runs the manor's museum and Knusbacka farmstead here.