John VI (Greek: Ιωάννης ΣΤ΄, Iōannēs VI ) was Ecumenical Patriarch of Constantinople from 712 to 715.
John VI was placed on the patriarchal throne in 712 by Emperor Philippikos, as a replacement for the deposed Patriarch Kyros. John was favored by Philippikos, because he shared his Monothelite sympathies. The religious policy of the new patriarch and his emperor caused the temporary rupture of relations with the Catholic Church. However, in 715 the new Emperor Anastasios II deposed John VI and replaced him with the Orthodox Patriarch Germanos I.