Friedrich Eugen, Duke of Württemberg (21 January 1732 – 23 December 1797) was the fourth son of Karl Alexander, Duke of Württemberg, and Princess Maria Augusta of Thurn and Taxis (11 August 1706 – 1 February 1756).

After serving with Frederick the Great during the Seven Years' War, he took up residence in 1769 at his family's exclave, the County of Montbéliard, of which he was also made lieutenant-general in March 1786 by his eldest brother, Charles Eugene, Duke of Württemberg,[1] who had begun to come into the inheritance of portions of the County of Limpurg in the 1780s.

[1] The next year he was named governor of the margraviate of Ansbach-Bayreuth by King Frederick William II of Prussia, to whom it had been sold by the last prince of that branch of the House of Hohenzollern.

[1] He acquiesced to the Treaty of Paris (7 August 1796) [de] with revolutionary France, in which his claims to Montbéliard and all other territories on the left bank of the Rhine River were renounced.

[1] Frederick Eugene retained, however, France's recognition of the integrity of the Duchy of Württemberg itself.