François d'Aguilon (also d'Aguillon or in Latin Franciscus Aguilonius) (4 January 1567 – 20 March 1617) was a Jesuit, mathematician, physicist, and architect from the Spanish Netherlands.

D'Aguilon was born in Brussels; his father was a secretary to Philip II of Spain. He became a Jesuit in Tournai in 1586. In 1598 he moved to Antwerp, where he helped plan the construction of the Saint Carolus Borromeus church. In 1611, he started a special school of mathematics in Antwerp, fulfilling a dream of Christopher Clavius for a Jesuit mathematical school; in 1616, he was joined there by Grégoire de Saint-Vincent. The notable geometers educated at this school included Jean-Charles della Faille, André Tacquet, and Theodorus Moretus.

His book, Opticorum Libri Sex philosophis juxta ac mathematicis utiles, or Six Books of Optics, is useful for philosophers and mathematicians. It was published by Balthasar I Moretus in Antwerp in 1613 and illustrated by the famous painter Peter Paul Rubens. It included one of the first studies of binocular vision. It also gave the names we now use to stereographic projection and orthographic projection, although the projections themselves were likely known to Hipparchus. This book inspired the works of Desargues and Christiaan Huygens.

He died in Antwerp, aged 50.