Conradin Kreutzer or Kreuzer (Messkirch in Baden, 22 November 1780 – Riga, 14 December 1849) was a German composer and conductor. His works include the opera Das Nachtlager in Granada, and Der Verschwender (Incidental music), both produced in 1834 in Vienna. In 1840 he became conductor of the opera at Cologne. His daughters, Cecilia and Marie Kreutzer, have been sopranos of some renown.