Franciszek Ksawery Brzezinski was a Polish composer.
Brzezinski had piano lessons with Jan Kleczyński. He studied law in Tartu and worked until 1903 as a lawyer. He then studied music in Paris and at the Conservatory in Leipzig. Since 1916, he lived as a composer in Warsaw.
He composed in addition to late romantic piano works, a piano concerto and a violin sonata.