Jiri Jonas (born April 1, 1932, Prague, Czech Republic) is a professor emeritus of chemistry in the Center for Advanced Study at the University of Illinois at Urbana-Champaign. Jiri Jonas is considered a pioneer in the use of magnetic resonance imaging at high pressure, developing techniques to study the dynamic structure of liquids and proteins. This approach has been used in the study of the arc repressor, a DNA-binding protein containing 53 amino acid residues.