Theorin is a frequent performer at leading opera houses in cities such as London, Milan, New York and Munich. Her relationship with the Gran Teatre del Liceu began in the 2012/13 season, when she starred in Tristan und Isolde on the occasion of the visit the prestigious Bayreuth Festival's orchestra and chorus paid to Barcelona. Since then she has played other heroines here, notably Brünnhilde in Götterdämmerung (2015/16), which earned her the prize for the best female singer in the Critics' Awards organized by Amics del Liceu.