The Max-Reger-Institute (MRI) is a musicological research institute and archive in Karlsruhe, Germany, dedicated to the work of the composer Max Reger, a representative of German music around the turn of the 20th century.

A main objective was to collect the autographs which had been dispersed during two world wars, and to establish an archive as a base for research.

[2] The archive holds autographs of sketches, scores and corrections from all periods and genres of Reger's compositions, also many of his handwritten letters and postcards to friends, publishers, performers and notable contemporaries.

[1][3] The library holds prints of first editions as well as later ones, international literature about Reger and related topics, sound documents, and copies of manuscripts that are not part of the MRI's archive.

[2] A focus of the MRI has been to provide access to the material related to Reger, to researchers, musicians and music lovers.