Charles August (9 July 1768 – 28 May 1810) was a Danish prince. He is best known for serving as Crown Prince of Sweden briefly in 1810, adopted by Charles XIII, before his sudden death from stroke. Earlier, he had been a general in the Royal Danish Army as well as the Danish Governor-general of Norway. His name before assuming the Swedish title in 1810 was Christian August of Schleswig-Holstein-Sonderburg-Augustenborg; Christian August of Augustenborg for short.