John Marchesinus (called in Latin Johannes Marchesinus and in Italian Giovanni Marchesini) was an Italian Franciscan friar, probably of the late thirteenth and early fourteenth centuries, who was the author of religious works. Little is known of Marchesinus, apart from what is said in his own work. Even the date of his life is uncertain and in the words of P. S. Allen "has been put both at 1300 and at 1466".