Ponte Sant'Angelo, originally the Aelian Bridge or Pons Aelius, is a Roman bridge in Rome, Italy, completed in 134 AD by Roman Emperor Hadrian, to span the Tiber from the city centre to his newly constructed mausoleum, now the towering Castel Sant'Angelo. The bridge is faced with travertine marble and spans the Tiber with five arches, three of which are Roman; it was approached by means of a ramp from the river. The bridge is now solely pedestrian and provides a scenic view of Castel Sant'Angelo. It links the rioni of Ponte, and Borgo, to which the bridge administratively belongs.

The ancient Romans were the first civilization to build large, permanent bridges. Early Roman bridges used techniques introduced by Etruscan immigrants, but the Romans improved those skills, developing and enhancing methods such as arches and keystones. There were three major types of Roman bridge: wooden, pontoon, and stone. Early Roman bridges were wooden, but by the 2nd century stone was being used. Stone bridges used the arch as their basic structure, and most used concrete, the first use of this material in bridge-building.