Pappano was born to Italian immigrant parents in Epping, Essex, UK, on December 30, 1959. His father was a chef who was a tenor singer and a voice teacher on the side. Pappano started piano at age six. After several years, he resolved to make the piano a career. When Pappano was 13, his family moved to Bridgeport, Connecticut, so that his father could take a full-time music teaching job. Pappano took piano lessons with Norma Verrilli and held a variety of jobs that included being a pianist in a cocktail bar. Later he studied composition with Arnold Franchetti and conducting with Gustav Meier, but at the time, he had no ambition to become a conductor. He became a rehearsal pianist at the New York City Opera and then at the Frankfurt Opera. "The traditional route for conductors is via the piano, working with singers in the opera house. That's how it worked for me," he told the London Independent. Pappano also did rehearsal work with the Lyric Opera of Chicago, and there he attracted the attention of conductor Daniel Barenboim. Barenboim hired Pappano as an assistant, and in 1987, Pappano made his debut at the Norwegian Opera. By 1990, he was the music director there, and in 1992, he was named to the same position at the Théâtre Royal de la Monnaie in Brussels.
The following year, Pappano caught a major break when he subbed for an ailing Christoph von Dohnányi, leading a new Vienna State Opera production of Wagner's Siegfried. Guest conducting appearances at houses in Britain and around Europe followed. Late in the decade, he added orchestral appearances to his résumé, serving from 1997 to 1999 as a guest conductor of the Israel Philharmonic and appearing with the Chicago Symphony and the Los Angeles Philharmonic, among many other orchestras. In 2002, Pappano was named the music director of the Royal Opera Covent Garden, a position he has held ever since. In 2005, he also became the music director of the Orchestra dell'Accademia Nazionale di Santa Cecilia in Rome, continuing to hold that position as of 2020.
Pappano has a substantial catalog of some 70 albums, predominantly, but not exclusively, devoted to opera. His 1996 debut, with the Orchestra and Choruses of the Théâtre Royal de la Monnaie, was a performance of Mendelssohn's oratorio Elijah. Pappano has recorded many of the core works of the Italian opera repertory for the EMI Classics label. He also conducts German and French opera enthusiastically, as well as a variety of instrumental music that has included a set of Leonard Bernstein's three symphonies with the Orchestra dell'Accademia Nazionale di Santa Cecilia in 2018. In 2020, Pappano conducted a new recording of Verdi's opera Otello, starring Jonas Kaufmann in the title role and, once again, featuring the Orchestra dell'Accademia Nazionale di Santa Cecilia. ~ James Manheim, Rovi