Frederick was the second son of Duke Friedrich Wilhelm I of Saxe-Weimar (1562–1602) from his second marriage to Anna Maria (1575–1643), daughter of Philipp Ludwig, Count Palatine of Neuburg.

Frederick and John Philip participated in the Princess Congress at Naumburg in 1614, where the inheritance alliance between Brandenburg, Hesse and Saxony was created.

The younger brothers decided to allow John Philip to continue to rule alone, when they came of age, in exchange for a jointure.

Friedrich went into the service of the Elector John George I of Saxony and fought in the Thirty Years' War in Lusatia and Bohemia.

Frederick's body was first interred in Hanover and later moved the Brothers' Church in Altenburg.