The Orpheus Monument is a Roman monument in Ptuj, Slovenia, an almost 5 metres (16 ft) high and about 1.8 metres (5 ft 11 in) wide stele, carved of white Pohorje marble. It is located at Slovene Square (Slovene: Slovenski trg), the town's central square, in front of the Town Tower. It is the oldest public monument preserved in its original location in Slovenia, the largest discovered monument from the Roman province of the Pannonia Superior, and the symbol of Ptuj.

The monolith was originally a grave marker, erected in the 2nd century AD to honor the memory of Marcus Valerius Verus, the duumvir (mayor) of Roman Poetovio. In the Middle Ages, it was used as a pillory. Criminals were tied to the iron rings attached to its lower part. Since March 2008, it has the status of a national cultural monument.