Jacob ben Machir ibn Tibbon (Hebrew: יעקב בן מכיר ׳ן תיבון), of the Ibn Tibbon family, also known as Prophatius, was a Jewish astronomer; born, probably at Marseilles, about 1236; died at Montpellier about 1304.
His Provençal name was Don Profiat Tibbon; the Latin writers called him Profatius Judæus.
Jacob occupies a considerable place in the history of astronomy in the Middle Ages.
His works, translated into Latin, were quoted by Copernicus, Reinhold, and Clavius.
In the controversy between the Maimonists and the anti-Maimonists, Jacob defended science against the attacks of Abba Mari and his party; the energetic attitude of the community of Montpellier on that occasion was due to his influence.