Count Magnus Fredrik Ferdinand Björnstjerna, (10 October 1779[1] – 6 October 1847[2]), was a Swedish count and military general, son of the envoy to Sachsen Magnus Olof Björnstjerna and his wife, countess Vilhelmina von Hagen.

At the age of 14, Björnstjerna was sent to Sweden, and attained the same year the rank of ensign (Swedish: fänrik) upon enrolling in The King's Guard.

[4] In 1812 he was appointed colonel of Kalmar Regiment,[5] and participated in the war in Germany, notably the attack on Dessau, the Battle of Fredrikort and other parts of the military campaigns.

In the same year he became the head of Field marshal Curt von Stedingk's staff, and was appointed to adjutant general of foreign affairs at the army in Norway, where he led the negotiations that led to the Convention of Moss of 1814.

[6] In 1815 he was created Baron (Swedish: friherre) stånd, count in 1826, he was appointed the Royal Order of the Seraphim in 1838 and in 1841 the Lord of the Realm.