Santo Stefano dei Cavalieri is a church in central Pisa located on Piazza dei Cavalieri (Knight's Square).

Construction began on 17 April 1565 in order to build a church for the Order of Knights of St Stephan, founded by the Grand Duke Cosimo de' Medici to fight Saracen piracy in the Mediterranean. The project with designs and oversight by Giorgio Vasari and David Fortini was to build a church on the site of an older church called San Sebastiano alle Fabbriche Maggiori, which dated at least to 1074. The new church on the site was consecrated by 21 December 1569. The facade, in white marble was designed by Don Giovanni de' Medici, illegitimate son of Cosimo I, with the help of Alessandro Pieroni; their designs were chosen over Vasari’s original plan. An inscription commemorates completion during the reign of Ferdinando I de' Medici.