Antipope Constantine II (d. 769?) was an Italian man who claimed the title of Pope in Rome in 767. The most powerful Lombard authorities considered his papacy invalid, and in spring 768 they deposed and imprisoned him. He was blinded in August after a rebellion attempted to restore him to power. In April 769, the Lateran Council had Constantine's tongue cut out for perjury. He was returned to prison, but the manner of his death is unknown.