The Navicella or Bark of St. Peter, of Old Saint Peter's Basilica in Rome, was a large and famous mosaic by Giotto di Bondone that occupied a large part of the wall above the entrance arcade, facing the main facade of the basilica across the courtyard. It depicted the version from the Gospel of Matthew of Christ walking on the water, the only one of the three gospel accounts where Saint Peter is summoned to join him. It was almost entirely destroyed during the construction of the new Saint Peter's Basilica in the 17th century, but fragments were preserved from the sides of the composition, and what is effectively a new work, incorporating some original fragments, was restored to a position at the centre of the portico of the new building in 1675.

Old St. Peter's Basilica was the church buildings that stood, from the 4th to 16th centuries, where St. Peter's Basilica stands today in Vatican City. Construction of the basilica, built over the historical site of the Circus of Nero, began during the reign of Roman Emperor Constantine I. The name "old St. Peter's Basilica" has been used since the construction of the current basilica to distinguish the two buildings.