Isaak Yakovlevich Pomeranchuk (Russian: ????´? ?´???????? ?????????´? (Polish spelling: Isaak Jakowliewicz Pomieranczuk); 20 May 1913, Warsaw, Russian Empire – 14 December 1966, Moscow, USSR) was a Soviet theoretical physicist working in particle physics (including thermonuclear weapons), quantum field theory, electromagnetic and synchrotron radiation, condensed matter physics and the physics of liquid helium.
The Pomeranchuk instability, the pomeron, and a few other phenomena in particle and condensed matter physics are named after him.