Petrus Apianus (real name Peter Bienewitz) (April 16, 1495 - April 21, 1557) was a German astronomer, cartographer and instrument maker .

Apianus's Cosmographia (1524) was the most popular book of its time on astronomy and geography. He also published the first table of sines (1534), and his Astronomicum Caesareum (1540) included his observations of comets.