Boris Karlov (Bulgarian: Борис Карлов; August 11, 1924 – December 14, 1964) was a Bulgarian accordionist. He was born in Sofia into a Romani (Gypsy) family. His father Karlo Aliev conducted an orchestra that was often heard on radio Sofia.^[1][2]

At an early age Boris was already passionate about folk music, played first on the ocarina and later on the tambura in his father's orchestra.^[3] Here he acquired a feeling for the harmonic structure of Bulgarian music. At the age of twelve, Karlov began to play the accordion, beginning with a simple 48-bass Hohner instrument, and progressing to a 120-bass. Eventually he had an Italian Scandalli accordion custom-made for him.

From 1950 to 1960, Karlov was in demand not only in Bulgaria, but also in Yugoslavia and Austria. He had a busy concert schedule and favourable reviews. Karlov developed a style of playing which was new on the accordion.^[4] Based on generally short, simple, but fast musical phrases, frequently in the irregular rhythms that were originally played on traditional Bulgarian instruments such as the gaida (bagpipe) and kaval (end-blown flute), he innovated a rondo form where the special character of Bulgarian music nevertheless remained.

He died, still on tour, in Kraljevo, of a kidney infection.