The collection of the Museum Schloss Moyland is based on the extensive art collection of the brothers Hans (1929–2002) and Franz Joseph (1933–2020) van der Grinten, one of the most important privately owned collections in North Rhine-Westphalia. Significant aspects of the visual and applied arts of the nineteenth to the twenty-first century are represented here. In addition to examples of international currents in modern art, a focus is placed on work groups by individual artists, including, among others, André Thomkins, Rudolf Schoofs, Erwin Heerich, and James Lee Byars.

The world’s largest collection of works by the artist Joseph Beuys forms the centre of the collection. Affiliated with this are the Joseph Beuys Archive and the museum library.

Focal points of the collection are prints and drawings as well as paintings, sculptures, and objects. The diversity of the collection is shown in changing presentations. The holdings of the Joseph Beuys Archive are also integrated into the exhibitions.