Alessandro Galilei (* 25. August 1691 in Florence; 21. December 1737 in Rome) was an Italian architect.
Galilei stayed in England from 1714 to 1719, but none of his projects were realized there. Here, however, he came into contact with Palladianism, which introduced him to the classical formal language. He then worked for the Grand Dukes Cosimo III de' Medici and Gian Gastone de' Medici in Florence as a fortress builder and architect. He did not gain importance until 1731, when Pope Clement XII called him to Rome. There he built the Corsini Chapel of San Giovanni in Laterano in 1732 and the façade of San Giovanni dei Fiorentini in 1734. His main work is the façade of San Giovanni in Laterano, built between 1733 and 1736. It is a classicist interpretation of the façade of St. Peter's Cathedral and was inspired by Christopher Wren. Galileo knew how to combine monumentality with taste and elegance.