| Alexander Rüstow | |
| Birth Date: | 13 October 1824 |
| Birth Place: | Brandenburg, Kingdom of Prussia |
| Battles: | Austro-Prussian War |
| Relations: | Wilhelm Rüstow (brother) Cäsar Rüstow (brother) |
Alexander Rüstow (13 October 1824 – 25 July 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 Cäsar 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.