Giannini made his film debut in a small part in I criminali della metropoli in 1965. He appeared in supporting roles in Anzio and The Secret of Santa Vittoria, and starred in the original version of Swept Away. In 1967, he was a special guest on an episode of Mina’s TV show “Sabato Sera”. In 1971, he appeared in E le stelle stanno a guardare, a television adaptation of A. J. Cronin’s novel, The Stars Look Down.
Giannini won a Cannes Film Festival Award for Best Actor for his performance in Love and Anarchy (1973). In 1976, he starred in Seven Beauties, for which he was nominated for the Academy Award for Best Actor. Giannini is known for his starring roles in films directed by Lina Wertmüller. In addition to Seven Beauties and Swept Away, he also appeared in The Seduction of Mimi, Love and Anarchy, A Night Full of Rain, and Francesca e Nunziata.
Giannini has also achieved some international success. His fluency in English has brought him a number of featured roles in Hollywood productions, most notably as Inspector Pazzi in Hannibal. He also appeared in Man on Fire. Giannini played Alberto Aragón in A Walk in the Clouds in 1995, and Emperor Shaddam IV in the 2000 Dune miniseries. In 2002, he starred in the horror film Darkness. He later portrayed French agent René Mathis in the James Bond films Casino Royale (2006) and Quantum of Solace (2008).
Voice acting career
Giannini has had a successful career as a voice actor and dubber. He helped with the foundation of the C.V.D. along with Renato Turi, Corrado Gaipa, Valeria Valeri, Oreste Lionello, Wanda Tettoni and other dubbers.
Giannini is the official Italian voice dubber of Al Pacino. Both he and Ferruccio Amendola were the primary dubbers of Pacino until Amendola’s death in 2001 when Giannini became the sole voice dubber. He also dubbed Jack Nicholson’s voice as Jack Torrance in the Italian release of The Shining and the Joker in Batman and Michael Douglas as Gordon Gekko in Wall Street and the 2010 sequel as well as dubbing other actors such as Dustin Hoffman, Gérard Depardieu, Ryan O’Neal, Jeremy Irons, Mel Gibson, Tim Allen, Leonard Whiting and Ian McKellen in some of their work.
In Giannini’s animated roles, he voiced Carl Fredricksen (voiced by Ed Asner) in the Italian dub of the Pixar film Up. He also provided the Italian voice of Raul Menendez in the Call of Duty game franchise. Outside of dubbing, he provided a voice role in the 2001 Italian animated film Momo in which he voiced the main antagonist.