The article consists of two parts. The first covers the history of opera and ballet from its inception in Ljubljana after 1600 to the present. The opera and ballet arts in Ljubljana are still housed in the structure that was constructed in 1892. Since then, with the exception of the period of the First World War, opera and ballet performances in the Slovenian language have been held continuously in Ljubljana. The second part presents the current mission of the public institution, the Slovenian National Theatre Opera and Ballet Ljubljana, its activities and organisational structure, as well as the management of records and archives based on the classification plan adopted in 2021.