Charles of Aquitaine (c. 825/830 - 4 June 863) was the Archbishop of Mainz from 856 until 863. Charles was a son of King Pepin I of Aquitaine. In 849 he was captured by King Charles the Bald and from 851 until 854 he was imprisoned in a monastery. He escaped in 854. On 6 March 856 King Louis the German appointed him the Archbishop of Mainz. He died in 863 and was buried in the Abbey of St Alban.