The Bach-Archiv Leipzig or Bach-Archiv is an institution for the documentation and research of the life and work of Johann Sebastian Bach. The Bach-Archiv also researches the Bach family, especially their music. Based in Leipzig, the city where Bach lived from 1723 until his death, the Archiv is recognised by the German government as a "cultural beacon" of national importance. Since 2008 the Bach-Archiv has been part of the University of Leipzig.
The Bach-Archiv was founded on the occasion of the bicentennial of Bach's death in 1950 by Werner Neumann, who remained its director until 1973. It served as a central archive for manuscripts and historic documents connected to the composer and a central research center related to him and his family.
At the time of the institution's foundation Leipzig was in East Germany. Prior to German unification there was collaboration with Bach experts in West Germany. For example, the second edition of Bach's complete works, the Neue Bach-Ausgabe, was a joint project between the Bach-Archiv and the Johann-Sebastian-Bach-Institut in Göttingen, West Germany. After unification the Bach-Archiv became part of the Konferenz Nationaler Kultureinrichtungen, a union of more than twenty cultural organizations in the former East Germany which are deemed to be nationally significant. The Göttingen Institute closed in 2006. Since 23 November 2008 the Bach-Archiv has been an institute of the University of Leipzig.
The Bach-Archiv has been housed in the historic Bosehaus opposite the Thomaskirche since 1985. The site was restored from 2008 to 2010 to comply with the latest safety requirements, and was opened again on 20 March 2010 by the President of Germany, Horst Köhler. The Neue Bachgesellschaft shares the premises, which also houses a Bach Museum.
Today the Bach-Archiv is a renowned center of Bach research with a scientific library for Bach topics. There is engagement with a wider public via the Bach-Museum and via performances of Bach's music, especially the Bachfest Leipzig (an international festival) and the Internationaler Johann-Sebastian-Bach-Wettbewerb (an international music competition).