Aribo (died 1031) was the Archbishop of Mainz from 1021 until his death. He was Primate of Germany during the succession of Conrad II.
Aribo disputed with the Diocese of Hildesheim the jurisdictional right over Gandersheim Abbey, but Pope Benedict VIII found in favour of Hildesheim, a ruling which Aribo further disputed and ignored, without however denying the pope's right to judge. Aribo also grieved the cathedral chapter of the Diocese of Worms after they elected and the new king appointed a bishop without his (Aribo's) approval in 1025. Aribo also disapproved of Conrad's marriage to Gisela on the basis of consanguinity, challenging its legality.
Aribo expanded the economy of Thuringia by minting coinage at Erfurt, the oldest market and trading centre in the province.
Aribo had consecrated Saint Gotthard as bishop of Hildesheim on December 2, 1022.