Bolesław Szabelski (3 December 1896 in Radoryż - 27 August 1979 Katowice) was a Polish composer of modern classical music. While his style shifted and varied over the course of his life, he is best known for his atonal work composed during the 1950s and 1960s.

Szabelski studied at Polish Musical Society School with Łysakowski in 1915. He attended the Warsaw Conservatory under Karol Szymanowski. Between 1929 and 1939, he taught organ and composition at the conservatoire of Katowice.

Szabelski began working in the neoclassical and romanticism modes typical of the early 20th century. He adopted the serialist technique in the 1950s and was one of a number of Polish new wave of composers to embrace atonality. His early work had been characterised by monumental forms and fanfare motifs and Szabelski adapted to the new astetic while retaining his old signatures. As a result he developed a style described as "strikingly innovative".

He composed five symphonies (1926, 1934, 1951, 1956 and 1968), as well as concertos, chamber and choral works. Szabelski was highly influential on the "New Polish School" composers of the early 1950s, and had a formative influence on his student Henryk Mikołaj Górecki.