Stephen Oyoung is an American actor and voice actor. He is best known for portraying Martin Li / Mister Negative in the 2018 video game Spider-Man and its 2023 sequel.

Mister Negative is a supervillain appearing in American comic books published by Marvel Comics. The character is usually depicted as an enemy of Spider-Man, the Punisher, Shang-Chi, and Cloak & Dagger. The character was created by Dan Slott and Phil Jimenez, and first appeared in "Swing Shift", a story in Free Comic Book Day: The Amazing Spider-Man #1. The name "Mister Negative" is a reference to photographic negative, as the colors of his skin, hair, and costume are inverted when he transforms into his alter ego.