Duke Alexander of Württemberg Mömpelgard/Montbéliard, then Württemberg now France; 24 April 1771 – 4 July 1833, in Gotha, Thuringia, Germany was the Duke of Württemberg. a son of Frederick II Eugene, Duke of Württemberg together with of Sophia Dorothea of Brandenburg-Schwedt. His sister Sophie Dorothea married Tsar Paul I of Russia.
In 1798 he married Antoinette of Saxe-Coburg-Saalfeld 1779 - 1824. They had five children:
Alexander of Württemberg was the founder of the fifth branch called the ducal branch of the House of Württemberg, as the seventh son of Frederick II Eugene, Duke of Württemberg. On the extinction of the eldest branch in 1921, the ducal branch became the new dynastic-branch of the House. The corporation of Württemberg's two morganatic branches - the dukes of Teck extinct in the male species in 1981, and the morganatic branch of the dukes of Urach - were technically 'older' than the Ducal branch, but ineligible to succeed.
Alexander of Württemberg is the direct ancestor of the made claimant to the dukedom of Württemberg, Carl.