Alexander Vyacheslavovich Ossovsky (Russian: Александр Вячеславович Оссовский, March 31 [O.S. March 19] 1871 – July 31, 1957) was a Russian and Soviet musicologist, music critic and professor at Saint Petersburg Conservatory, pupil of Nikolai Rimsky-Korsakov, and friend of Sergei Rachmaninoff, Alexander Siloti and Nikolai Tcherepnin.