Franciszek Lessel (1780 – December 26, 1838) was a Polish composer.
Lessel was born in Puławy. His father, Wincenty Ferdynand Lessel, was a pianist and composer of Czech origin who served as his first teacher. In 1799 Franciszek Lessel went to study with Joseph Haydn and continued to do until the man's death. He worked as a court musician, headed Warsaw's Amateur Music Society, and gave lessons on how to play the glass harmonica. In later life he largely had non-musical administrative and inspector jobs. He died in Piotrków Trybunalski.
Among his most noted pieces is Fantaisie in E minor, which was dedicated to Cecylia Beydale. Bedayle was for a time his lover until they discovered they had the same mother.