Guido Di Naccio is an Italian voice actor born in Switzerland and raised in Abruzzo, Italy. He studied acting at the Accademia Flaiano in Pescara, where his teachers included prominent voice actors Roberto Pedicini and Christian Iansante, as well as actress Alba Bucciarelli. He also gained theatrical experience under the guidance of director Sabatino Ciocca at the Teatro Marrucino in Chieti.

Di Naccio has built a extensive career dubbing voices for both live-action and animated productions. While he is widely recognized for his live-action dubbing of actors such as Gabriel Macht as Harvey Specter in the series Suits, his work in animation is equally varied. He is particularly well-known for voicing the character Silco in the acclaimed animated series Arcane.

In the realm of anime and animated series, Di Naccio's filmography includes a significant number of roles. He has been a recurring presence in the Pretty Cure franchise, providing voices for multiple entries. He is credited as the voice of Kaoru in Fresh Pretty Cure and its associated special Fresh Precure! Omocha no Kuni wa Himitsu ga Ippai!?, as Kumojacky in Heartcatch Precure, and as Dorodoron in Futari wa Precure Splash Star. His other anime and animation voice credits include Valtor in Winx Club, Riff Tamson in Star Wars: The Clone Wars, Toffee in Star vs. the Forces of Evil, Orm and Ray in Young Justice, Biowulf in Generator Rex, and Vincent Van Ghoul in Scooby-Doo! Mystery Incorporated. He also voiced the character Manabu Matsudo in the series Live On Cardliver Kakeru and Kyo Misumi in Kotetsushin Jeeg, though specific details on these roles are not detailed in the available records.

Beyond television, Di Naccio has lent his voice to characters in video games, most notably as Kayn in the widely popular game League of Legends. He has also contributed voices to other major game titles, including the Star Wars Jedi series, Ghost of Tsushima, and Wet.