Felix Ruvimovich Gantmacher (Russian: Феликс Рувимович Гантмахер) (23 February 1908 – 16 May 1964) was a Soviet mathematician, professor at Moscow Institute of Physics and Technology, well known for his contributions in mechanics, linear algebra and Lie group theory. In 1925–1926 he participated in seminar guided by Nikolai Chebotaryov in Odessa and wrote his first research paper in 1926. Gantmacher collaborated with Mark Krein on Oscillation Matrices and Kernels and Small Vibrations of Mechanical Systems. In 1939 he contributed to the classification problem of the real Lie algebras.