Lohengrin, WWV 75, is a Romantic opera in three acts composed and written by Richard Wagner, first performed in 1850. The story of the eponymous character is taken from medieval German romance, notably the Parzival of Wolfram von Eschenbach, and its sequel Lohengrin, itself inspired by the epic of Garin le Loherain. It is part of the Knight of the Swan legend.

Wilhelm Richard Wagner was a German composer, theatre director, polemicist, and conductor who is chiefly known for his operas. Unlike most opera composers, Wagner wrote both the libretto and the music for each of his stage works. Initially establishing his reputation as a composer of works in the romantic vein of Carl Maria von Weber and Giacomo Meyerbeer, Wagner revolutionised opera through his concept of the Gesamtkunstwerk, by which he sought to synthesise the poetic, visual, musical and dramatic arts, with music subsidiary to drama. He described this vision in a series of essays published between 1849 and 1852. Wagner realised these ideas most fully in the first half of the four-opera cycle Der Ring des Nibelungen.