Xilomantzin was the tlatoani ("king") of the pre-Columbian altepetl (ethnic state) of Culhuacan in the Valley of Mexico from 1440 to 1473. Xilomantzin was the son of , the previous ruler of Culhuacan, and or , a daughter of Tezozomoctli, ruler of Azcapotzalco. He succeeded his father in the year 13 Flint (1440). He married Izquixotzin, the daughter of Tlacateotl, ruler of Tlatelolco, and had a son named Acolmiztli.