Museum of Brittany, Regional museum in Rennes, France.

The Museum of Brittany occupies part of Les Champs Libres, a building by architect Christian de Portzamparc opened in 2006 between Rennes station and the old town. Its facade pairs a dark stone lower wall, pierced by a long rectangular window, with a convex grid of glass panes above. Inside, more than 600,000 objects and documents trace Breton history from prehistory onward, including over 400,000 photographic negatives and prints.

The museum's core collections come from the 1794 revolutionary confiscations, notably the cabinet of curiosities of Christophe-Paul de Robien (1698–1756), president of the Parliament of Brittany. The first "Musée de Rennes" was officially created on 16 October 1805, when the city acquired full ownership of the seized collections. Between 1805 and 1850 the collections moved repeatedly, from the Visitation church to the Carmelite convent, the bishop's palace, the town hall and the law school chapel. In 1975–1976 the Musée de Rennes was split into the Museum of Brittany and the Museum of Fine Arts, and in 2006 the museum moved into Les Champs Libres, designed by Christian de Portzamparc.

The museum's Breton ethnography began with objects entered in the inventory from 1890 and catalogued from 1909; a "Musée breton" with two rooms, one for Haute-Bretagne and one for Basse-Bretagne, opened in 1913. Collecting continued between the wars, and since 1987 the Bintinais ecomuseum near Rennes has held the region's rural and agricultural collections jointly with the museum.

The museum is located within the Les Champs Libres cultural complex and offers wheelchair access throughout. The layout is straightforward, making it easy to navigate the galleries at your own pace.

The museum holds around 6,800 items related to the Dreyfus affair, including personal letters and documents. This important collection arrived as a donation from Jeanne Lévy, Alfred Dreyfus's daughter, following an exhibition in 1973.