Alessandro Maria Gaetano Galilei (25 August 1691 – 21 December 1737) is a Florentine mathematician, architect and theorist, a member of the same patrician family as Galileo.
He receives architectural and engineering training from Anton Maria Ferri, an outstanding figure of the Accademia dei Nobili, who lectures and writes a treatise on perspective, fortifications and artillery.
With him, young Galilei works on the study of building techniques, stereometry, hydraulics.