Schloss Philippsruhe not only has the municipal wedding hall, event halls and catering facilities, but has also provided rooms for the Historical Museum of the City of Hanau since 1967. This regional museum for Hanau history, culture and art history is supported by the city of Hanau and the Hanauer Geschichtsverein 1844 e. V. The collection focuses on Hanau art, arts and crafts from the 17th to the 20th century and the city's history. Since 2019, the second floor of the right side wing has been home to the GrimmsMärchenReich, a family participatory museum. A visible storage is currently being installed in the gallery spaces on the top floor. The new Paper Theater Museum is scheduled to open on the second floor of the south wing by the end of 2022.

The park of Schloss Philippsruhe can be counted among the authentic Grimm sites; it was there that Philipp Wilhelm Grimm and Dorothea Zimmer, the parents of Jacob and Wilhelm Grimm, became engaged in 1782.