Duke Alexander of Württemberg (9 September 1804, Saint Petersburg – 4 July 1885 Tüffer) was the father of Francis, Duke of Teck and the grandfather of Mary of Teck, wife of King George V.

His father was Duke Louis of Württemberg, brother of King Frederick I of Württemberg and Empress Maria Feodorovna of Russia. His mother was Henrietta of Nassau-Weilburg, a great-granddaughter of King George II of Great Britain through his eldest daughter Anne, Princess Royal and Princess of Orange.

In 1835, he married, morganatically, Claudine Rhédey von Kis-Rhéde (1812-1841), by whom he fathered three children: Claudine, Francis and Amalie. His wife was created Countess of Hohenstein in her own right and, following the rules of morganatic marriages, the children inherited their mother's title as Count or Countess of Hohenstein from birth. They had no rights through their father to any royal status or inheritance.

In 1841, his wife was killed—run over by horses—and he became mentally unstable, a condition which lasted for the rest of his life.

In 1863, his three children were elevated to the rank of Prince and Princesses of Teck by King William I of Württemberg.

In 1871, his son Francis was created Duke of Teck by King Charles I of Württemberg, five years after his marriage with Alexander's third cousin (in descent from King George II of Great Britain), Princess Mary Adelaide of Cambridge. The Duchy of Teck was a peerage title in the former Kingdom of Württemberg. Alexander's daughters were not given any new status, and remained Princesses of Teck.