John I Megas Komnenos Axouchos (Greek: Ιωάννης Α΄ Μέγας Κομνηνός Αξούχος, Iōannēs I Megas Komnēnos Axoukhos) was Emperor of Trebizond from 1235 to 1238.
He was the eldest son of Alexios I of Trebizond and Theodora Axuchina, and was perhaps still a minor at the time of his father's death in 1222, as the throne passed to his brother-in-law, Andronikos I Gidos.
John succeeded on his brother-in-law's death in 1235 and had a brief and uneventful reign of three years, dying in 1238 from an accident while playing tzykanion, a variant of polo fashionable among the Byzantine nobility. His young son Ioannikios was put into a monastery and his second brother Manuel I ascended the throne, the second time a son was passed over in favour of another relative. Some sources suggest Ioannikios reigned briefly before abdicating and became a monk.