Boleslav Leopoldovich Yavorsky[a][b] (Russian: Болесла́в Леопо́льдович Яво́рский; 22 June 1877 – 26 November 1942)[1] was a Soviet and Russian musicologist, music teacher, administrator, and pianist.

Through his teachings and editorial positions he heavily influenced Soviet music theory.

He chaired the music section of the People's Commissariat for Education (Narkompros) from 1922 to 1930.

Yavorsky was a friend, mentor and confidant of the composer Dmitri Shostakovich and played an important role in the latter's development.

[3] His students included Rostislav Berberov, Vladimir Aleksandrovich Dukelsky (also known as Vernon Duke), Alexei Fedorovich Kozlovsky, Alexander Abramovich Krein, Sergei Protopopov, Mykola Leontovych, Tatiana Grigorievna Shaborkina (director of the Scriabin Museum from 1941 until 1984), Maria Wiłkomirska, and Isaak Rabinovich, whose son Boleslav Rabinovich was named after Isaak's beloved teacher.