Charles XV & IV (May 3, 1826 –  September 18, 1872) is King of Sweden (Charles XV) and Norway (Charles IV) from 1859 until his death.

Though known as King Charles XV in Sweden (and also on contemporary Norwegian coins), he is actually the ninth Swedish king by that name, as his predecessor Charles IX (reigned 1604–1611) had adopted a numeral according to a fictitious history of Sweden.