The Costa or St Catherine Chapel (Italian: Cappella Costa or Cappella di Santa Caterina) is located in the south aisle of the Basilica of Santa Maria del Popolo in Rome. This is the fourth side chapel from the counterfaçade and was dedicated to St Catherine of Alexandria. The lunettes were painted by the helpers of Pinturicchio and the marble altar-piece is attributed to Gian Cristoforo Romano.