Anton Joseph Weidenbach (9 April 1809 in Linz am Rhein – 21 November 1871 in Wiesbaden) was a German schoolteacher, archivist and historian, who specialized in history of the Rhineland.
From 1825 he attended the teacher's training school in Brühl, and from 1829 to 1835 worked as a schoolteacher in the town of Bacharach. Afterwards he taught classes at the municipal school in Ahrweiler, where he also worked as city archivist. In 1840 he obtained his qualification to teach in secondary schools from the University of Bonn. With Bonn professors Karl Simrock, Gottfried Kinkel and historian Johann Christian von Stramberg, he maintained frequent correspondence.
In 1848 he made speeches in favor of the revolutionary activities taking place in Germany. Fearing reprisal after suppression of the Hecker uprising, he temporarily fled to Belgium. In 1849 he returned to Germany, and found employment as a teacher at the higher Töchterschule in Bingen. In 1864 he retired from teaching and moved to Wiesbaden, where he worked as a statistician.
Following the death of Johann Christian von Stramberg in 1868, he continued publication of the massive Rheinischer Antiquarius with five additional volumes (34 volumes total).