A graduate in composition of Pesaro's Conservatorio Rossini, where he also studied orchestral conducting, he made his professional opera debut with Il barbiere di Siviglia in Salerno on Oct. 12, 2005.
The success of a November 2007 filmed run of Simon Boccanegra at the Teatro Comunale di Bologna, opening the season there, led to Mariotti's appointment as the theater's direttore principale, to start the next year, a title he would hold until his promotion in 2014.
and Dallapiccola's Il prigioniero (2011); Le nozze di Figaro (2012); Norma with Mariella Devia and Nabucco (2013); Così fan tutte and, Michael Spyres and Carlos Álvarez, Guillaume Tell in 2014; Die Zauberflöte, the conductor's first German-language project, and, with Gregory Kunde, Un ballo in maschera (2015); Attila with Ildebrando d’Arcangelo, filmed by RAI TV, and Werther with Flórez (2016); and in 2017 La voix humaine with Anna Caterina Antonacci and Cavalleria rusticana.
[13] In 2012 he led Carmen at the Metropolitan Opera and he has since returned to conduct four other productions with that company,[14] making DVDs of Rigoletto for Deutsche Grammophon[15] and La donna del lago for Erato.
[19][20] During the Bologna company's September 2011 tour to Japan, Mariotti led performances of Carmen, starring Nino Surguladze, and I puritani, with Desirée Rancatore, Celso Albelo, Luca Salsi and Nicola Ulivieri, at Tokyo Bunka Kaikan, as well as events outside the capital.
[29][30][31] Later the same year, he led his first performances of two French operas, both featuring Flórez: Les Huguenots at the Deutsche Oper in Berlin[32] and the above-mentioned Werther in Bologna.