Jill is a protagonist in the original Resident Evil, where she is introduced as a member of the fictional U.S. police special force Special Tactics And Rescue Service (STARS).She returned as the protagonist in Resident Evil 3: Nemesis, where she was no longer a member of STARS, merely a citizen trying to survive the zombie outbreak in Raccoon City, and then in Resident Evil: The Umbrella Chronicles and in Resident Evil 5, where she was a member of the fictional paramilitary group Bioterrorism Security Assessment Alliance (BSAA). She is also the protagonist in Resident Evil: Genesis, the mobile phone adaptation of the series. Jill appears in the films Resident Evil: Apocalypse and Resident Evil: Afterlife, portrayed by Sienna Guillory.
Jill Valentine first appears as one of two playable protagonists in the original Resident Evil game. Along with Chris Redfield, she is a member of STARS' Alpha team, with background in the U.S Army's Delta Force. The Alpha team were deployed to investigate a series of bizarre murders in the Arklay Mountains, where they discover and enter the Umbrella Corporation's Arklay Research Facility. Jill initially works with Barry Burton, as they inspect the mansion and discover its undead residents. She and Chris discovered that STARS leader Albert Wesker had betrayed them, and after defeating the Tyrant released by Wesker, Jill escaped the mansion along with Chris, Barry, STARS Bravo team member Rebecca Chambers, and Alpha team pilot Brad Vickers.
Jill returns as the sole protagonist in Resident Evil 3: Nemesis, where she fights alongside Carlos Oliveira, an Umbrella mercenary soldier who is attempting to escape Raccoon City. Jill encounters Nemesis, a super soldier created by the Umbrella Corporation. After several encounters with the creature, she is able to defeat it and escape Raccoon City before the city is destroyed. Jill then appears in Resident Evil: The Umbrella Chronicles where she works with Chris Redfield to expose and destroy the Umbrella Corporation. She and Chris defeat Umbrella's newest BOW, TALOS, and survive the ordeal.
Before the events of Resident Evil 5, Jill had apparently died to save Chris during a confrontation with Wesker. During the game, Chris finds out that she had survived, but is now under Wesker's control. Chris and his new partner Sheva Alomar manage to subdue Jill and allow her to regain control and return to her normal self. Jill then worked with fellow BSAA agent Josh Stone to assist Chris and Sheva in defeating Wesker once and for