Der Barbier von Bagdad (The Barber of Baghdad) is a comic opera in two acts by Peter Cornelius to a German libretto by the composer, based on The Tale of the Tailor and The Barber’s Stories of his Six Brothers in A Thousand and One Nights. The first of three operas by Cornelius, the piece was first performed at the Hoftheater in Weimar on 15 December 1858.

Cornelius planned the work as a one-act comedy, but on the advice of Franz Liszt expanded it to two. Franz Liszt later arranged the second overture for orchestra (S.352). Unlike most German comic operas of the period, which have spoken dialogue, Der Barbier von Bagdad is through composed. Cornelius offered the inventive and complex opera as an alternative to the contemporary German opera composers such as Richard Wagner, whose ideological fervor he found overwhelming.

At its first performance the opera was a failure, and it was not played again in the composer’s lifetime. The composer's mentor and friend Franz Liszt conducted the premiere. However, political actions by the director of the theater resulted in demonstrations against Liszt and the so-called neo-German school of composition. The opera closed after only one performance, and Liszt resigned his post. Cornelius also left Weimar.

In the late 19th century two versions were made, by the noted Wagnerian conductors Felix Mottl and Hermann Levi. In New York the work was first played in 1890 by the Metropolitan Opera House Company and in London in 1891. Finally, in June 1904, the original version as composed by Cornelius was again staged in the Weimar Hoftheater, this time to popular approval and critical acclaim.

In the 20th century, the opera was performed infrequently abroad but held its own in German opera companies using the original text, rather than Mottl’s or Levi’s revisions. It has a minor niche in the operatic repertoire.