Paul Kochanski (born Paweł Kochański; 14 September 1887 – 12 January 1934) was a Polish violinist, composer and arranger active in the United States.
Paweł Kochański was born in Odessa, then part of the Russian Empire, to Polish-Jewish parents and studied violin first with his father and then at age 7 with Emil Młynarski, whose teacher had been Leopold Auer. In 1898 Młynarski went to Warsaw, and upon founding the Warsaw Philharmonic Orchestra in 1901, summoned Kochanski, then aged 14, to be its concertmaster. He also took charge of his upbringing and education, treating him like a son and stating that he believed he would become a world-class soloist. In 1903, with sponsorship from leading Warsaw families arranged by Młynarski, Kochanski went to Brussels to study with César Thomson at the Brussels Conservatoire. There, after four months, he received the Premier prix avec la plus grande distinction (First prize, with the greatest distinction).
It was at this point, as he was beginning his itinerant virtuoso career, that he met Arthur Rubinstein, through the invitation of Juliusz Wertheim. They immediately realised their shared musical sympathies, but the friendship, rich with youthful energy, really took off in 1907 with their concerts for the Warsaw Philharmonic, including duo performances of Beethoven's Kreutzer Sonata and Tchaikovsky's Piano Trio with the cellist J. Sabelik. In 1908, with Jozef Jaroszyński (a patron of Kochanski's), they made a triumphant tour of European capitals, including Berlin, Paris, London and Karlsbad, and in 1908–9 Kochanski and Rubinstein performed the Franck Violin Sonata in A, the Kreutzer again, and a Brahms trio (with Eli Kochański, a cellist and Paul's gifted brother) for the Warsaw Philharmonic.