Ceitho was a 6th-century Welsh abbot and saint who resided in West Wales. As a descendant of the king Cunedda Wledig, he was reportedly one of five brothers, including Gwynno, Gwynoro, Celynin, and Gwyn, who were all recognized as saints. These siblings are credited with establishing the village of Llanpumsaint in Carmarthenshire. Following his lineage, he was also the son of Cynyr Farfdrwch of Cynwyl Gaeo.