Robert P. Molyneux SJ (July 24, 1738 – December 9, 1808) was an English-American Catholic priest and Jesuit missionary to the United States. Born to a prominent English family, he entered the Society of Jesus and studied at the College of St Omer in France. When the school moved to Bruges, Belgium, he followed, becoming a master. In 1771, he emigrated to the United States as a missionary, where he took up pastoral work in Philadelphia.