The archives of Sal. Oppenheim jr. & Cie. reflect more than two centuries of history of the Bank and the Oppenheim family. It was designated in Cologne in 1939, and is thus the oldest private bank archive in Germany.

The history of the Bank, which was founded in 1789, is of central importance to both internal communication and the Bank's public image. One of the bank archives' main tasks is to communicate the historical information both internally and externally. They are also open to members of the public for research purposes.

A large proportion of the archived material is made up of the Bank's diverse commitments to the economic development of Cologne and the Rhineland area. The files cover a broad range of subjects from the railway industry, through heavy, electrical and construction industries, insurance and banking, to public sector finance. The archives also contain private correspondence of Oppenheim family members and documentation of their contributions to politics, culture and society, be it as citizens of Cologne or Jews in Prussia. The extensive bequest of Orient-explorer and archaeologist Max von Oppenheim is also housed in the archives, as are items from collections such as photographs, glass negatives, historical securities and medals. A research library is also incorporated.