Mahler most often refers to Gustav Mahler, Bohemian-Austrian composer and conductor. His family included:
Alma Mahler-Werfel (1879–1964), Austrian socialite and wife of, successively, Gustav Mahler, Walter Gropius and Franz Werfel
Anna Mahler (1904–1988), Austrian-UK sculptor, daughter of Gustav and Alma Mahler
Fritz Mahler (1901–1973), Austrian conductor, and cousin once removed of Gustav Mahler
Otto Mahler (1873–1895), Bohemian-Austrian musician and youngest brother of Gustav Mahler
Joseph Mahler (1900–1981), inventor of the Vectograph stereoscopic technique, cousin of Gustav Mahler
Zdeněk Mahler (born 1936), Czech pedagogue, writer, publicist and musicologist, distantly related with Gustav Mahler
Other people named Mahler (German for "someone who grinds") include:
Arthur Mahler (1871–1944), Austrian archeologist
Bruce Mahler (born 1950), US actor
David Mahler (born 1944), US hammered dulcimer player
Eduard Mahler or Ede Mahler (1857–1945), Hungarian-Austrian orientalist, astronomer, natural scientist
Gregory Mahler (born 1950), administrator and U.S. Political Science scholar and professor
Halfdan T. Mahler (1923−2016), Dane, former Director-General of the World Health Organization (WHO)
Hedwig Courths-Mahler (1867–1950), German writer
Horst Mahler (born 1936), German lawyer and political extremist
Kurt Mahler (1903–1988), mathematician
Margaret Mahler (1897–1985), Hungarian psychoanalytic child psychologist
Mickey Mahler (born 1952), U.S. baseball player
Nicolas Mahler (born 1969) Austrian Artist
Rick Mahler (1953–2005), U.S. baseball player
Vincent A. Mahler (born 1949), U.S. political science scholar and professor