Augustus of Saxe-Weissenfels (13 August 1614 in Dresden – 4 June 1680 in Halle), was a Duke of Saxe-Weissenfels-Querfurt of the House of Wettin and administrator of the Archbishopric of Magdeburg.

On 23 January 1628, at the age of 13, August was appointed administrator of the Archbishopric of Magdeburg by its Chapter to replace the current holder of that title, Christian Wilhelm of Brandenburg.

The Peace of Prague (1635) confirmed his rule over the city, but three years later, Swedish troops expelled the Habsburg army and restored August as administrator as of 19 October 1638.

August finally took full control of Magdeburg on 31 December 1642 after a neutrality treaty was concluded with the Swedish general Lennart Torstenson.

They had twelve children: In Halle on 29 January 1672, two years after the death of his first wife, August married Countess Johanna Walpurgis of Leiningen-Westerburg.