John Michael Kosterlitz is a Scottish born British-American physicist. He is a professor of physics at Brown University and the son of biochemist Hans Kosterlitz. He was awarded the 2016 Nobel Prize in physics along with David Thouless and Duncan Haldane for work on condensed matter physics. Professor Kosterlitz does research in condensed matter theory, one- and two-dimensional physics; in phase transitions: random systems, electron localization, and spin glasses; and in critical dynamics: melting and freezing.