Jakob Yngvason (born 23 November 1945) is an Icelandic/Austrian physicist and emeritus professor of mathematical physics at the University of Vienna. He has made important contributions to local quantum field theory, thermodynamics, and the quantum theory of many-body systems, in particular cold atomic gases and Bose–Einstein condensation. He is co-author, together with Elliott H. Lieb, Jan Philip Solovej and Robert Seiringer, of a monograph on Bose gases