Corderius is the Latinised form used by Mathurin Cordier (c. 1479 – 1564), a teacher, theologian and grammar expert from Lausanne, Switzerland. He was born to a peasant family in Normandy. He pursued theological studies, which he completed in Paris. While he briefly ministered as a priest, his talent as a teacher of grammar was quickly recognised, and he spent most of his life teaching.
Initially, he taught in various locations in France. His pupils included John Calvin, and the two men forged a life-long friendship. Cordier converted to Protestantism under the influence of Robert Estienne, who edited and printed a collection of his works. As hostility to the religion rose in France, he fled to Geneva, Switzerland in 1527. There he taught alongside Calvin, and became director the School of Lausanne. In 1559 he returned to Geneva, where he accepted another teaching position.
Cordier wrote several books for children, most famously his Colloquia (Colloquiorum scholasticorum libri quatuor), which was used in schools for three centuries after his time.