Leser Landshuth (15 January 1817 – 23 March 1887) was a German Jewish liturgiologist. He went to Berlin as a youth to study Jewish theology, and there he became acquainted with Leopold Zunz and Abraham Geiger, the latter of whom was then staying in that city in order to become naturalized in Prussia. Landshuth soon gave up his intention of becoming a rabbi, not being willing to conceal or renounce his liberal opinions; and aided him in establishing himself as a Hebrew bookseller.