Petrus Bertius (also Peter Bertius; (in Dutch) Pieter de Bert) (14 November 1565 – 13 October 1629) was a Flemish philosopher, theologian, historian, geographer and cartographer. Bertius published much in mathematics, and historical and theological works, but he is now best known as cartographer with his edition of the Geographia of Ptolemy (based on Mercator's edition from 1578), and for its atlas.
