John Toner is a theoretical physicist and Professor Emeritus at the University of Oregon, with a primary research focus in condensed matter physics. He predicted that soap is the best soundproofing material, and that quasicrystals are the hardest. He was awarded the American Physical Society's 2020 Onsager Prize in Statistical Physics for his pioneering work on flocking. He has also been the recipient of Simons and Gutzwiller Fellowships, and is a Fellow of the American Physical Society.