Karl Alexander
Karl Alexander may refer to:
- Karl Alexander, Duke of Württemberg, who served as Duke from 1698 until 1737
- Karl Alexander, 5th Prince of Thurn and Taxis, the 5th Prince of Thurn and Taxis
- Karl Alexander, Grand Duke of Saxe-Weimar-Eisenach, who served as Grand Duke from 1853 to 1901
- Karl-Alexander Island, also known as Zemlya Karla-Alexandra
- Karl Alexander , American writer and author of Time After Time
- Christian Frederick Charles Alexander, Margrave of Brandenburg-Ansbach, commonly known as Karl Alexander
- Karl Alexander Müller, Swiss physicist and Nobel laureate
- Carl Alexander Heideloff, German architect