On January 20, 2021, it was announced that Stark had signed a contract with WWE. On January 27, 2021, she wrestled her first match in the women's Dusty Rhodes Tag Team Classic. She was paired with Marina Shafir against Shotzi Blackheart and Ember Moon, but they did not win this match. On February 17, she made her NXT debut, defeating Valentina Feroz. A week later, she lost a match against Io Shirai. This was followed by more matches against Dakota Kai and Raquel González, where she lost both matches. On the NXT TakeOver: Stand and Deliver pre-show, she defeated Toni Storm. At The Great American Bash, Stark and Io Shirai defeated The Way (Candice LeRae and Indi Hartwell) to win the NXT Women's Tag Team Championship. They lost the titles to Toxic Attraction (Gigi Dolin and Jacy Jayne) at Halloween Havoc in a triple threat tag team Scareway To Hell ladder match, involving Indi Hartwell and Persia Pirotta. On the November 2 episode of NXT, Stark was attacked backstage by Jayne and Dolin, where she suffered an injury.
On the July 19, 2022 episode of NXT, Stark made her return in the twenty-woman battle royal for the number one contendership for the NXT Women's Championship, in a winning effort. On the November 8 episode of NXT, Stark and Nikkita Lyons failed to win the NXT Women’s Tag Team Championships from Kayden Carter and Katana Chance. After the match, Stark attacked Lyons, turning heel for the first time in her career.
On January 28, 2023, Zoey Stark entered her first Royal Rumble match, entering at number thirteen before being eliminated by Sonya Deville. As part of the 2023 WWE Draft, Stark was drafted to the Raw brand. On the May 8 episode of Raw, Stark made her main roster debut, defeating Nikki Cross. At Night of Champions, Stark assisted Trish Stratus in her match against Becky Lynch by hitting her finisher, the Z-360, allowing Stratus to defeat Lynch. Stark defeated Natalya to qualify for the women's Money in the Bank ladder match on the June 5 episode of Raw. At Money in the Bank, Stark worked with Stratus throughout the namesake match to prevent Lynch from winning, including a failed attempt to restrain Lynch with handcuffs. Stratus, Stark and Lynch were defeated when Stark's former tag team partner Iyo Sky claimed the briefcase and won the match.
Stark, being accompanied by Stratus, wrestled her first main event match on the main roster on the August 28 episode of Raw in a falls count anywhere match against Lynch. Stark lost the match after she accidentally struck Stratus through a table, which allowed Lynch to put Stark through another table. At Payback, Stark attempted to aid Stratus in Stratus' steel cage match against Lynch in a failing effort. Stark then ended her alliance with Stratus when Stratus slapped and berated Stark after the match, seemingly turning face for the first time on the main roster.
On the September 4 episode of Raw, Stark lost to Shayna Baszler by technical submission after passing out to Baszler's Kirifuda Clutch. After the match, Baszler gave praise to Stark's toughness. The following week, Stark ran out to save Baszler when Baszler was attacked by Chelsea Green and Piper Niven after Baszler's match with Green. At Crown Jewel on November 4, Stark failed to win the Women's World Championship from Rhea Ripley in a fatal-five way match also involving Raquel Rodriguez, Nia Jax and Baszler, who Ripley pinned to retain the title. On the following episode of Raw, Stark won a battle royal for a Women's World Championship match against Ripley at Survivor Series. At the event on November 25, Stark failed to win the title. On Raw Day 1 on January 1, 2024, Stark teamed up with Baszler for the first time to defeat Tegan Nox and Natalya to become the number one contender for the WWE Women's Tag Team Championship. On the May 6 episode of Raw, Stark would compete in the Queen of the Ring tournament, where she defeated Ivy Nile in the first round. On the July 8 episode of Raw, Stark and Baszler aligned themselves with the returning Sonya Deville after weeks of declining the latter's offer, turning heel and later calling themselves Pure Fusion Collective. In December, Stark entered the tournament to crown the inaugural Women's Intercontinental Champion, where she lost in the semifinals. At the Royal Rumble on February 1, 2025, Stark entered the namesake match at number eight, where she helped Baszler and Deville eliminate Maxxine Dupri, but was eliminated by Bianca Belair and Naomi. On February 7, Deville's contract was not renewed by WWE, making PFC a tag team consisting of Stark and Baszler. On the April 11 edition of SmackDown, PFC took part in a tag team gauntlet match to earn a WWE Women's Tag Team Championship match at WrestleMania XL, but were defeated by Bayley and Women's Intercontinental Champion Lyra Valkryia. On May 2, Shayna Baszler was released by WWE, effectively ending PFC.
On the May 19 episode of Raw, Stark took part in a triple threat Money in the Bank qualification match against Rhea Ripley and Kairi Sane. During the match, as Stark attempted a missile dropkick from the top ropes, she landed awkwardly on her right knee and was removed from the match immediately. It was later confirmed that Stark would require surgery.