Petrinum may refer to:
Religion Munus petrinum, the concept of the Primacy of the Roman Pontiff in the Church of Christ
History The ancient village Petrinum on the site of the contemporary town of Mondragone, Italy
Educational institutions Bischöfliches Gymnasium Petrinum, a private school established in 1896 in Linz, Austria Gymnasium Petrinum Brilon, a state funded school established in 1655 in Brilon, Germany Gymnasium Petrinum Dorsten, a state-funded school established in 1642 in Dorsten, Germany Gymnasium Petrinum Recklinghausen, a state-funded school established in 1421 in Recklinghausen, Germany