Horwitz is a surname, and may refer to:

  • Bernhard Horwitz, chess player
  • Brian Horwitz, American major league baseball outfielder
  • Harry Moses Horwitz, aka Moe Howard, of the Three Stooges
  • Jerome Lester Horwitz, aka Curly Howard, of the Three Stooges
  • Maksymilian Horwitz, aka Henryk Walecki (1877–1937), leader and theoretician of the Polish communist movement
  • Morton Horwitz (born 1938), legal historian and law professor
  • Samuel Horwitz, aka Shemp Howard of the Three Stooges
  • Steven Horwitz, American economist
  • Tony Horwitz
  • William Horwitz, Scientist Emeritus, formerly an analytical chemist at the Food and Drug Administration, USA
  • Yosef Yozel Horwitz, rabbi
  • Horwitz Publishing House, Australian publisher of popular and pulp fiction, established in NSW in 1921
  • Louisa Gross Horwitz Prize