Jean-Baptiste Pater was a French rococo painter.

Born in Valenciennes, Pater was the son of sculptor Antoine Pater and studied under him before becoming a student of painter Jean-Baptiste Guide. Pater then moved to Paris, briefly becoming a pupil of Antoine Watteau in 1713. Watteau, despite treating Pater badly, had a significant influence on him. However the two quarreled and Pater returned to Valenciennes, where he remained for two years. In 1721, Pater and the dying Watteau reconciled; subsequently Pater became a student of Watteau once again, although only for a month before the latter's death. Pater later claimed to have learnt everything he knew during those few weeks with Watteau. He was accepted into the Académie in 1728, presenting a large military work in the popular Watteau style: La Rejouissance des Soldats (Louvre).