Johan von Fircks (died January 3, 1667) was a Danish officer.
That same year he married the widow of Ditlev Rantzau til Clewitz, Anna van der Wisch, a daughter of Johan van der Wisch.
[1][2] That he was considered an experienced officer familiar with war is indicated by the fact that Frederick III of Denmark called him home from Norway in order to take part in the negotiations with the diet at Odense in February 1657, when it had nearly been decided to go to war against Sweden.
[1][3]: 18 In April that same year he was appointed deputy commander of the Norwegian army under Iver Krabbe.
[3]: 47 He distinguished himself in the campaign, and he was promoted to major general and named commander at Fredrikstad Fortress in 1663,[4][5] where he died.