The Theater an der Wien (The Theatre on the Wien River) is a historic theatre on the Left Wienzeile in the Mariahilf district of Vienna. Completed in 1801, it has seen the premieres of many celebrated works of theatre, opera, and symphonic music. Since 2006, the theatre has served primarily as an opera house, hosting its own company.
The theatre was the brainchild of the Viennese theatrical impresario Emanuel Schikaneder, who is best known to history as Mozart's librettist and collaborator on the opera The Magic Flute (1791). Schikaneder's troupe had already been successfully performing for several years in Vienna in the smaller Theater auf der Wieden, where The Magic Flute had premiered. Schikaneder, whose performances often emphasized spectacle and scenery, felt ready to move to a larger and better equipped venue.