Carl also Karl Romanus von[1] Weishaupt (11 August 1787 – 18 December 1853) was a Bavarian lieutenant general and War Minister under Maximilian II of Bavaria from 5 April to 21 November 1848.

He studied at the University of Altdorf and was taught by Franz Xaver von Zach in Gotha.

He took part primarily as an infantryman, then as an artillerist in the campaigns of the Bavarian army during the years 1805 to 1815, since 1812 in the rank of a Hauptmann, and became prisoner of war until 1813.

In 1826 he was advanced to major, and served as head of division for artillery affairs in the Bavarian war ministry until 1829.

His youngest brother Alfred (1795–1872) was a higher council for mining and salines (Oberberg- und Salinenrat) in Berchtesgaden, and was knight (Ritter) of the Order of Merit of the Bavarian Crown (Verdienstorden der Bayerischen Krone) and member of the Order of Saint Michael.