Stefano Billi, sometimes credited as Stefano Gajani Billi, was an Italian voice actor known for his extensive work in dubbing films, television series, and animated productions. Born in Rome on June 23, 1961, he built a career characterized by versatility across many genres until his death on March 25, 2025.

His voice can be heard in numerous anime series and films for the Italian market. He provided the Italian voice for the character Trowa Barton in the film Mobile Suit Gundam Wing: Endless Waltz Special Edition. He also voiced the character Bosh in the new Italian dubbing of the anime series My Patrasche, also known as Il mio amico Patrasche.

Beyond these roles, Billi's work in anime was prolific. His other credits include Dayakka Littner in Gurren Lagann, Kaneo Takarada in Kill la Kill, Allen in Carole & Tuesday, Gregory Lestrade in Case File nº221: Kabukicho, Maeda in Devilman Lady, Tentomon in Digimon Adventure 02, Narumi in Gakuen Alice, Dr. Zaijien in Gintama, Hisamitsu Noto in Toradora!, Hajime Hirata in Star Blazers 2199, Nakamura in Summer Time Rendering, and the character Luak in Black Lagoon. He also contributed to films such as Wolf Children, where he voiced Maestro Tanabe, Millennium Actress, Redline, and Tekken: Blood Vengeance.