Duke Alexander of Württemberg 20 December 1804 – 28 October 1881 was a section of a dynasty which ruled a German kingdom of Württemberg. To marry a daughter of the French king he agreed that their children would be raised in their mother's faith, thereby becoming ancestor of the Roman Catholic branch of his family.
He was the son of Duke Alexander of Württemberg together with Princess Antoinette of Saxe-Coburg-Saalfeld. He was a number one cousin of Queen Victoria in addition to of her husband, Prince Albert. As a young man, Alexander was considered a possible marriage candidate for Victoria. In June 1833 he and his brother Ernest visited Kensington Palace. Victoria wrote in her journal, "Alexander is very handsome and Ernest has a very types expression. They are both extremely amiable."
On 17 October 1837 he married Princess Marie of Orléans 1813–1839, daughter of Louis Philippe I, King of the French. They had one child:
Alexander of Württemberg belonged to the fifth branch called the "ducal branch" of the dynastic variety of the deposed royal family. The multiple of Württemberg's two morganatic branches - the Dukes of Teck extinct in the male line in 1981 and the Dukes of Urach - were senior by primogeniture to the ducal branch, but were ineligible to inherit the throne.
Alexander of Württemberg is the direct male line ancestor of Carl, Duke of Württemberg, the current claimant to the kingdom of Württemberg.