Karl Alexander Grand Duke of Saxe Weimar Eisenach
- Category : 1818-births
- Type : PSP
- Profile : 5/1 - Heretical / Investigator
- Definition : Split - Small (48)
- Incarnation Cross : LAX Prevention 1
Grand Duke of Saxe-Weimar-Eisenach from 1853 until his death on 5 January 1901.
In The Hague, on 8 October 1842, Karl Alexander married his first cousin, Princess Sophie of the Netherlands, daughter of Willem II and Grand Duchess Anna Pavlovna of Russia, sister of his mother. They had four children.