Georgy Lvovich Catoire (Russian: L'vovič Katuar; French: Georges Catoire) (Moscow, April 27, 1861–May 21, 1926) was a Russian composer of French heritage.

He studied piano in Berlin with Karl Klindworth (a friend of Richard Wagner) from whom he learned to appreciate Wagner. Catoire became one of the few Russian 'Wagnerite' composers, joining the Wagner society in 1879. It is partially due to his steadfast loyalty to Wagner that Catoire's works are relatively unknown today: most of Rimsky-Korsakov's circle strongly disliked Wagner, which explains why Wagner's music was barely known by the Russian public or musicians. Rimsky-Korsakov and his circle were less supportive of Catoire than they might have been had Catoire been less enthusiastic about Wagner.

Catoire graduated from Moscow University in mathematics in 1884 with outstanding honours. Upon graduating, Catoire worked for his father's commercial business, only later becoming a full-time musician. It was at this time that Catoire began taking lessons in piano and basic harmony from Klindworth's student, V. I. Willborg. These lessons resulted in the composition of a piano sonata, some character pieces, and a few transcriptions. The most famous of these transcriptions was the piano transcription of Tchaikovsky's Introduction and Fugue from the First Orchestral Suite (which Jurgenson later published at the recommendation of Tchaikovsky).

Not satisfied with his lessons with Willborg, Catoire went to Berlin in late 1885 to continue his lessons with Klindworth. Throughout 1886, Catoire made brief trips to Moscow, and on one of these trips, he became acquainted with Tchaikovsky, who was greatly pleased with Catoire's set of piano variations. Tchaikovsky told the younger composer that, "it would be a great sin if he did not devote himself to composition". It was during this visit to Moscow in which Catoire was introduced to the publisher Jurgenson. Catoire continued to study piano with Klindworth in Berlin throughout 1886, and simultaneously studied composition and theory with Otto Tirsch. Not satisfied with Tirsch's instruction, he began study with Philip Rufer. These lessons were also short-lived but resulted in the composition of a string quartet.

Catoire returned to Moscow in 1887. He declined to debut as a concert pianist in spite of Klindworth's recommendation. Catoire met Tchaikovsky again, and he showed him (along with Gubert and Sergei Taneyev) the string quartet which he had written in Berlin for Rufer. They all agreed that the work was musically interesting but lacking in texture. On the recommendation of Tchaikovsky, Catoire went to St. Petersburg to Rimsky-Korsakov with a request for composition and theory lessons. In a letter to Rimsky-Korsakov, Tchaikovsky later described Catoire as, "very talented... but in need of serious schooling."

Rimsky-Korsakov gave Catoire one lesson before passing him to Lyadov. This single lesson resulted in three piano pieces which were later published as Catoire's op.2. With Lyadov, Catoire studied counterpoint and wrote several pieces, including the lovely Caprice op.3. Lyadov's lessons concluded Catoire's formal schooling.

After returning to Moscow, Catoire became quite close to Anton Arensky. During this period, Catoire wrote his second quartet (which he later rewrote as a quintet) and his cantata, "Rusalka", op.5, for solo voice, women's chorus and orchestra.

Catoire's family, friends, and colleagues were not sympathetic to his choice of career in composition, so in 1899, after a series of disappointments, Catoire withdrew to the countryside and nearly stopped composing entirely. After two years of withdrawal from society, having broken off almost all connections with musical friends, the op.7 Symphony emerged in the form of a sextet as a result of this seclusion.

From 1919 he was professor of composition in the Moscow Conservatory. He wrote several treatises on theory and composition during his tenure. Nikolai Myaskovsky considered students of Catoire with great regard.

Today he is very little known, although a few recordings exist of his piano works by Marc-Andre Hamelin and Alexander Goldenweiser, and David Oistrakh recorded the complete violin music. His music has a certain semblance to the works of Tchaikovsky, the early works of Scriabin, and the music of Fauré. Catoire's compositions demand not only high virtuosity but also an ear for instrumental colour.

Georgy Catoire is the uncle of author and musician Jean Catoire.