Dr. Sam Isaacs is a scientist that features in the Resident Evil movie series.
He was an Umbrella Corporation researcher who was involved in the Nemesis Program with Major Timothy Cain. He led the team of scientists at the Raccoon City Hospital who experimented on Alice to prepare her for her battle against Nemesis, and later he experimented on her further at a secluded Umbrella laboratory in Detroit to give her a variety of psychic powers. Although upon escaping Alice killed many of the scientists and guards within the facility, Isaacs survived to enact a secret protocol programmed into Alice during her time there, putting her (presumably) under Umbrella's control. However she soon broke free and disappeared.
After the fall of civilization due to the zombie apocalypse, Isaacs became the head of an underground laboratory in the desert outside of Las Vegas. Here, he cloned Alice using blood samples acquired from her time at the Detroit lab, and attempted to "re-create" her by putting the clones through a series of tests mimicking the real Alice's experiences. These all ended in failure. At the same time, Umbrella chairman Albert Wesker tasked Isaacs with finding a way to domesticate the zombies to end their threat, although these experiments also ended in failure. However as a side-effect Isaacs discovered that the zombies were made stronger, and when Alice was located in Las Vegas he disobeyed Wesker's orders and took a crateload of these "super zombies" to go and capture her.
The mission was a complete disaster. Only Isaacs and his pilots survived, and while escaping in their helicopter Isaacs was bitten by one of the "super zombies" and infected with a new strain of the T-Virus. Upon returning to the lab he tried to cure himself by injecting massive amounts of anti-virus, but he soon mutated into a Tyrant-like monstrosity, killed security chief Slater, then went on a rampage and slaughter everyone else in the lab. When Alice found her way to the lab, she faced off against the Isaacs-Tyrant and finally killed him, with the help of one of her clones, by luring him into the lab's test-run mockup of the laser hallway where the monster was sliced into cubets by the laser grid.
- Named for actor Jason Isaacs, who was originally considered for the role. As an in-joke, Isaacs' name was given as "J. Isaacs" in a briefly-shown computer readout in Resident Evil: Extinction.
- Resident Evil: Extinction: