Born in Mantua, he completed his studies in Parma where he graduated in Marketing at the Faculty of Economics and at the same time in singing at the Conservatory. Since 2007 he has participated in the biennium of the Teatro alla Scala Academy under the guidance of Leyla Gencer during which he had the opportunity to perform in concerts and operas (Così fan tutte).
He will continue to collaborate with La Scala as Guglielmo in Le convenienze teatrali, Alberto in L’occasione fa il ladro, Ernesto in Don Pasquale, participated in the Monteverdi Trilogy as Telemaco and Nerone (the latter role performed also at Carnegie Hall), Tempo in Il trionfo del tempo e del disinganno and Nagg in the world premiere of Fin de partie by Kurtag, revived in Amsterdam and soon at the Budapest Spring Festival and the Theater de Chatélet.
Thanks to his versatile repertoire, that makes him feel at ease from Monteverdi to Mozart, from Belcanto to Verdi, to the 1900s and contemporary music, he is a regular guest of theatres such as La Fenice (Don Giovanni, Così fan tutte, Elisir d'amore, Traviata, Věc Makropulos, Diary of one who disappeared, Mirandolina, Cefalo e Procri), Maggio Musicale Fiorentino (Dido and Aeneas, Apollo in Dafne of M. da Galliano, Admeto in Alceste and Tamino in Die Zauberflöte) and in Verona (Aeneas, Tamino e Nemorino at Filarmonico and Don Ottavio and Tybalt in Roméo et Juliette in Arena). He has been also performing at San Carlo di Napoli (Aureliano in Zenobia in Palmira of Paisiello, Alfredo, Fenton in Falstaff), at Comunale di Bologna (Don Ottavio and Luigi Belgiojoso in Risorgimento! of Ferrero), at Massimo di Palermo (Tracolin in Le Toreador of Adam), at Petruzzelli di Bari (Fenton), at Lirico of Cagliari (Camille in La vedova allegra), at the Teatri del Circuito Lombardo (Fadinard in Il cappello di paglia di Firenze), at the Festival della Valle d'Itria of Martina Franca (Idraote in Armida of Traetta and Capelio in Giulietta e Romeo of Vaccaj) and Rossini of Wilbad (main role in Don Giovanni of Pacini).
Alongside to his operatic career he has also an intensive concert activity.
Leonardo Cortellazzi has been collaborating with conductors such as Alessandrini, Chailly, Chung, Conlon, Dantone, Fasolis, Matheuz, Mehta, Montanari, Oren, Ranzani, Rustioni and Santi and with stage directors such as Audi, Carsen, Flimm, Hampe, Michieletto, Pizzi, Ronconi, Vick, Wilson.
Among his recent and future engagements Nemorino in Muscat and Naples, Don Ottavio in Liège where he just returned in the title role of La clemenza di Tito, Carolino in Che originali! of Mayer at Festival Donizetti in Bergamo, Alfredo in Treviso, Admet in Lisbona where he formerly debuted Percy in Anna Bolena and where he will be returning as Leicester in Maria Stuarda, Un servo in Luci mie traditrici of Sciarrino and Alfredo at La Fenice, Ferrando at Teatro del Maggio Musicale for the Da Ponte trilogy with Fabio Luisi and a new production of Fin de partie at Theater Dortmund.