Alexander Rüstow (October 13, 1824 – July 25, 1866) was a Prussian soldier and military writer from Brandenburg an der Havel. The brother of Wilhelm Rüstow and Cäsar Rüstow, he is remembered for his work Der Küstenkrieg (Berlin, 1848). Alexander and Caesar both fell on the field of battle during the 1866 Austro-Prussian War, with Alexander dying at Horitz from wounds sustained in the Battle of Königgrätz.