Alexander Seaton or Seton was a Scottish soldier in Danish service during the Thirty Years' War. He briefly served as a governor in the Battle of Stralsund and as an admiral in the Torstenson War.

The siege of Stralsund was a siege laid on Stralsund by Albrecht von Wallenstein's Imperial Army during the Thirty Years' War, from 13 May 1628 to 4 August 1628. Stralsund was aided by Denmark and Sweden, with considerable Scottish participation. The lifting of the siege ended Wallenstein's series of victories, and contributed to his downfall. The Swedish garrison in Stralsund was the first on German soil in history. The battle marked the de facto entrance of Sweden into the war.