Giulio Alvise Caselli was born in Ferrara, where he studied violin at the Conservatorio and graduated with honors in German and English Languages and Literatures from the Universities of Ferrara and Regensburg.

He began studying singing under the guidance of his mother, the soprano Maria Gabriella Munari, and graduated in Vocal Technique from the University of Music and Performing Arts in Munich. During his academic journey, he was a member of the Bavarian Theatre Academy and specialized in Lieder with Helmut Deutsch. He also attended masterclasses with artists such as Mirella Freni, Thomas Hampson and Luciana Serra.

In 2005, he made his debut in Richard Strauss's Ariadne auf Naxos in a co-production between the Teatro Saô Carlos in Lisbon and the Teatro Comunale in Ferrara, under the direction of Zoltán Peskó and stage direction of Toni Servillo. Shortly thereafter, he performed the role of Ned Keene in Benjamin Britten's Peter Grimes at the Teatro Comunale in Modena, broadcast on Radio3 Rai.

Since 2006, he has been a soloist with permanent ensembles at theaters in Dortmund, Linz, Augsburg, and Meiningen. Additionally, he has appeared in theaters in Salzburg, Aachen, Wuppertal, Hagen, Novara and Reggio Emilia. He has also performed in notable venues such as the Konzerthaus Berlin, the Riga Baroque Festival, the Cantiere Internazionale d'Arte di Montepulciano and the Rheingau Musik Festival.

His extensive repertoire includes roles such as Figaro in The Barber of Seville (Dortmund, Würzburg, Augsburg), Papageno in The Magic Flute (Konzerthaus Berlin), Don Giovanni (Augusta, Salzburg, Venice Biennale 2010), Count Almaviva in The Marriage of Figaro, Æneas in Purcell's Dido and Aeneas and Astolfo in Antonio Vivaldi's Orlando Furioso (Daegu Opera House, South Corea).

One of his most acclaimed roles has been Pelléas in Debussy's Pelléas et Mélisande at the Augsburg Opera.

He is also particularly active in modern and contemporary repertoire, with significant experience in world premieres. He has performed in works such as Luigi Nono's Intolleranza 1960 and has been recognized for his role as Hans Scholl in Udo Zimmermann's Weiße Rose.

Among his most recent roles are Guglielmo in Così fan tutte, Biterolf and Wolfram von Eschenbach in Wagner's Tannhäuser, and Pasquale in Haydn's Orlando Paladino. In 2016, he recorded for Naxos the role of Argante in the modern premiere of Johann Simon Mayr's opera Amore non soffre opposizioni.

He has collaborated with internationally renowned directors and conductors, including Francesco Micheli, Toni Servillo, Peter Konwitschny, Christine Mielitz, Doris Dörrie, Cesare Lievi, Dirk Kaftan, Roland Böer, Markus Poschner, Federico Maria Sardelli, Mirga Gražinytė-Tyla and Thomas Guggeis.

Active in the concert repertoire as well, he has performed major Lieder cycles by Schubert and Mahler, Carmina Burana by Carl Orff as well as oratorios by Berlioz, Mendelssohn and Bach.

He lives in Germany, where he serves as a lecturer in Vocal Performance at the University of Augsburg.