Marc Saez is a French actor, voice director, adapter, and director born on November 25, 1967 in Marseille. He studied applied foreign languages before training at the conservatory of Marseille. His early career included work as a radio host on stations such as Forum 92, NRJ, and Fun Radio, as well as performing in theater productions of classical plays by Molière and Marivaux.

Saez is highly active in the field of dubbing, providing the French voices for numerous international actors including Naveen Andrews, James Nesbitt, Lou Diamond Phillips, and Michael Kelly. He was also the regular voice for actor Gerard Butler early in his career.

Within animation, he is known for several major voice roles. He is the French voice of Gyokko, one of the primary antagonists and an Upper Rank demon in the Swordsmith Village Arc of Demon Slayer: Kimetsu no Yaiba. He also voices the character Corkus, a captain in the Band of the Hawk, in the film trilogy Berserk: The Golden Age Arc. His other notable animation roles include the young genius Dexter in Dexter's Laboratory, the mischievous cat Nermal in Garfield and Friends, the titular character in Marsupilami, and the Joker in numerous DC Universe animated films such as Batman: The Killing Joke and Batman Ninja.

Beyond voice acting, Saez has extensive experience behind the scenes as a director and adapter. He has supervised the French dubbing for several films and television series. Notably, he worked as the adapter and voice director for the French version of the popular series Squid Game. He also handled audio direction and provided a voice for the film Oxygen, directed by Alexandre Aja, a filmmaker with whom he has had a long-standing professional relationship since the early 1990s.