Jakob Yngvason (born 23 November 1945) is an Icelandic/Austrian physicist and emeritus professor of mathematical physics at the University of Vienna.

He is co-author, together with Elliott H. Lieb, Jan Philip Solovej and Robert Seiringer, of a monograph on Bose gases.

For their theoretical work in thermodynamics, Yngvason and Lieb received the Levi Conant Prize of the American Mathematical Society in 2002, for a paper on the mathematical explanation of the second law of thermodynamics.

[2] In 2004,he received the Erwin Schrödinger Prize of the Austrian Academy of Sciences.

Yngvason is married to Guðrún Kvaran, professor of lexicography at the University of Iceland; they have two children.