Viktor Vladimirovich Wagner, also Vagner (Russian: Виктор Владимирович Вагнер) (4 November 1908 – 15 August 1981) was a Russian mathematician, best known for his work in differential geometry and on semigroups.
Wagner was born in Saratov and studied at Moscow State University, where V.F. Kagan was his advisor. He became the first geometry chair at Saratov State University. He received Lobachevsky Medal in 1937.