Italian Mannerist architect, painter, and theorist, who introduced the principles of ancient Roman architecture into France.

Trained by his father as a painter, Serlio went to Rome in 1514, where he studied architecture under Baldassarre Peruzzi, one of the initiators of the Mannerist style of architecture. With the sack of Rome in 1527, he fled to Venice, where he remained until 1540, when King Francis I of France employed him as a consultant in the building of the palace of Fontainebleau. Only two extant structures, however, can be attributed to Serlio: a doorway at Fontainebleau and the chateau of Ancy-le-Franc, begun in 1546.

Although Serlio's buildings were not influential, his treatise Tutte l'opere d'architettura, et prospetiva (1537–75; “Complete Works on Architecture and Perspective”) exerted immense influence throughout Europe. It was translated into English in 1611 and into other European languages.

The treatise was the first architectural handbook that emphasized the practical rather than the theoretical aspects of architecture, and it was the first to catalog the five orders. Serlio was also the first to incorporate illustrations into an architectural handbook, using drawings of Peruzzi and Bramante, as well as his own. Serlio's treatise was influential because it was a practical handbook of classical Greco-Roman style and presented a number of models for copying; it was fundamentally a set of illustrations linked by commentary rather than an essay on aesthetics or archaeology. Estraordinario libro, the last book of the treatise to be published in his lifetime, contained 50 fanciful designs for doorways, which were much copied in northern Europe and decidedly influenced the course of Mannerist architectural decoration.