Ritterhaus Museum, Regional history museum in Offenburg, Germany.

The Ritterhaus Museum is a regional museum in Offenburg with three floors of natural history, city artifacts, and cultural collections. The building itself dates to the 18th century and once belonged to the Imperial Knights family of Ortenau.

Carl Frowin Mayer, a district secretary, began building a municipal collection in 1894 and opened the Museum for Natural History and Ethnology in 1900 in the St. Andreas Hospital. From 1917 Ernst Batzer shifted its focus to local history, and in 1959 the collection moved into the former Ritterhaus, which the city had bought in 1958.

The colonial-era ethnological collection and the Cron big-game trophies are shown on the second floor in the exhibition 'A Window on the World', redesigned in 2017. The museum's name comes from the building, the Ritterhaus, which served the Ortenau Imperial Knights from 1803 to 1806.

The museum occupies the former Ritterhaus, a two-storey house with seventeen window axes and a three-storey central risalit topped by a triangular pediment. In the courtyard corner stands an 18th-century tower with a red sandstone spiral staircase winding without a newel up to the attic. The municipal archive is housed in the same building.

The 2015 "Wald – Land – Fluss" section of the natural history collection has hands-on stations where visitors can touch and try things out, alongside geological exhibits from the Ortenau. The museum's holdings total more than 10,000 objects.