The Tiber Island (Italian: Isola Tiberina, Latin: Insula Tiberina), is a boat-shaped island which has long been associated with healing. It is an ait, and is one of the two islands in the Tiber river, which runs through Rome; the other one, much larger, is near the mouth. The island is located in the southern bend of the Tiber. It is approximately 270 m. long and 67 m. wide.

The island has been linked to the rest of Rome by two bridges since antiquity, and was once called Insula Inter-Duos-Pontes which means "the island between the two bridges". The Ponte Fabricio, the only original bridge in Rome, connects the island from the northeast to the Field of Mars in the rione Sant'Angelo (left bank). The Ponte Cestio, of which only some original parts survived, connects the island to Trastevere on the south (right bank).

There is a legend which says that after the fall of the hated tyrant Tarquinius Superbus (510 BC), the angry Romans threw his body into the Tiber. His body then settled onto the bottom where dirt and silt accumulated around it and eventually formed Tiber Island. Another version of the legend says that the people gathered up the wheat and grain of their despised ruler and threw it into the Tiber, where it eventually became the foundation of the island.