He was born in Castiglione dei Pepoli (Bologna) in 1942, but he lives in Lodi, hometown of his wife, Adriana. After winning several competitions, in 1967 he made his debut at Teatro Sperimentale (A.Belli) of Spoleto as Figaro in IL BARBIERE DI SIVIGLIA.

He studied with M° Mario Bigazzi, completing his studies in Bologna with M° Giuseppe Marchesi. After having his career interrupted in 1970, he was persuaded to continue by M° Ottaviano Bizzarri.

Since its debut in 1977 with IL BARBIERE DI SIVIGLIA, he constantly sang at Teatro Alla Scala in Milan, participating in two season's opening.

For Teatro Alla Scala he recorded DON CARLO, two editions of AIDA, IL BARBIERE DI SIVIGLIA, SIMON BOCCANEGRA, IL TROVATORE, OTELLO, TOSCA, GIANNI SCHICCHI, with conductors such as Claudio Abbado, Riccardo Chailly, Riccardo Muti, Lorin Maazel, Sir Georg Solti. In 2007 he performed a historic concert on the occasion of the 30-year career at Teatro Alla Scala, an event that has been released on DVD (Leo Nucci: Trent'anni Alla Scala, produced by Cmajor).

In 1979 he made his debut at the Staatsoper in Vienna with IL BARBIERE DI SIVIGLIA. In this theater he sang nearly 300 performances and made several recordings, receiving the honor of “Kammersänger” and “Ehrenmitglied”.

At the Metropolitan in New York he made his debut in 1980 with UN BALLO IN MASCHERA. He participated in several new productions, recording UN BALLO IN MASCHERA, LA FORZA DEL DESTINO, L'ELISIR D'AMORE, IL BARBIERE DI SIVIGLIA and several Gala concerts.

His debut in London's Covent Garden was in 1978 with LUISA MILLER and since then, even with this theater he maintains a constant collaboration with performances and recordings.

He was singing in Arena di Verona for 31 years, performing in more than 100 performances, singing the role of RIGOLETTO for nine editions and recording various DVD.

He is probably the only baritone in history to have sung Rigoletto in all the most important theaters in the world, with a total of more than 450 official performances.
In recent years he has taken as "house" reference Teatro alla Scala in Milan, Zurich Opera House (debut in 1982 with LUISA MILLER) and the Teatro Regio of Parma (debut in 1967) , where recently he was awarded honorary citizenship. With these three theaters still maintains a special relationship, participating in many new productions.

He has recorded under the direction of Herbert von Karajan, Sir Georg Solti, Riccardo Muti, Claudio Abbado, Carlos Kleiber, Lorin Maazel, Riccardo Chailly, James Levine, Zubin Mehta, Carlo Maria Giulini, Giuseppe Patanè, Nello Santi, Bruno Bartoletti, Daniel Oren, collaborating with colleagues from the world of opera. He starred in two film-opera: MACBETH by Claude D'Anna presented at Cannes in 1987 and IL BARBIERE DI SIVIGLIA.

He has recently released a book dedicated to him: "Leo Nucci, un baritono per caso” written by Achille Mascheroni, Azzali edition of Parma.