The Mittelrhein-Museum (Museum of the Middle Rhine) is a museum in Koblenz dedicated to the art of the Rhine territory. It is one of the oldest public museum collections in Germany, the nucleus of which dates back to the honorary citizen Joseph Gregor Lang (1755- 1834), who left his rich collection of paintings to the city of Koblenz after his death.

Today, the museum's collection bears witness to more than 2,000 years of Rhineland art and cultural history. The collection includes about 1200 paintings, over 8000 graphic works, about 250 artistic photographs, 230 sculptures, and about 1000 objects related to the Rhine territory. There are also about 700 objects in stone, wood and metal, over 500 historical coins and medals and 345 ceramics. These are works by artists from the Rhine area that testify to the artistic and cultural development of the region from the Middle Ages to the modern era. Many paintings bear witness to Rhenish Romanticism, with depictions of Middle Rhine landscape motifs and city views.