1245 – 1310/14) was a Byzantine orator and monk, who was a leading opponent of the Union of the Churches in the reign of Michael VIII Palaiologos (r. 1259–1282).
In 1261, however, when Michael ordered the blinding and imprisonment of the legitimate emperor, John IV Laskaris (r. 1258–1261), Holobolos expressed public grief, and his lips and nose were mutilated as punishment.
In 1265/66, through the intervention of Patriarch Germanus III, Holobolos was able to get a post as a teacher, possibly at the orphanage of the Church of St. Paul.
Because of his fervent anti-Unionism, he was exiled to the Megalou Agrou monastery on the Sea of Marmara in 1273, and was not allowed to return to the capital until after Michael's death, when his son and successor Andronikos II Palaiologos (r. 1282–1328) repudiated the Union.
Thus Holobolos participated in the Council of Blachernae in 1285, which formally condemned the Union, and was restored to imperial favour: he received the title of rhetor and became protosynkellos by 1299.