The Princes' House (German: Prinzenhaus) in Plön in the North German state of Schleswig-Holstein is a former royal summer residence in the grounds of the park at Plön Castle. It is the only surviving maison de plaisance in Schleswig-Holstein.
It was given its present name because at the end of the 19th and beginning of the 20th century it was used as a residence and school for the sons of the German emperor, William II. At that time it was enlarged with two extensions. A farm on nearby Princes' Island served the princes as a learning site for agricultural skills.