In October 2014, Crews took part in a WWE tryout camp, resulting in him being offered a contract. Starting on December 31, 2014, multiple sources reported that Crews had come to terms on a contract with WWE. He reported to the WWE Performance Center, the home of their NXT developmental brand, on April 6, 2015. WWE officially announced Crews as part of a new class of NXT recruits in a press release on April 13. He made his first televised appearance on the May 6 episode of NXT, signing an NXT contract in a segment with William Regal. Crews started working NXT house shows the following month, under the ring name of Uhaa Nation.
On August 5, it was announced that Uhaa, now working under the new ring name Apollo Crews, would be making his televised NXT in-ring debut on August 22 at NXT TakeOver: Brooklyn. Crews made his debut at the August 13 tapings, which would air after NXT TakeOver: Brooklyn, defeating Martin Stone. At NXT TakeOver: Brooklyn, Crews defeated Tye Dillinger in his official debut match. At NXT TakeOver: Respect, Crews defeated Tyler Breeze. On the October 8 tapings of NXT, Crews won a battle royal to become the #1 contender to the NXT Championship. Crews received his title shot against Finn Bálor on October 22, winning the match, but not the title, by disqualification, when he was attacked by Baron Corbin, who held a grudge against Crews for eliminating him from the #1 contender's battle royal. The rivalry between Crews and Corbin led to a match at NXT TakeOver: London, which Corbin won. Crews had a small feud with Elias Samson after he saved Johnny Gargano from Elias' assault on the March 23, 2016, NXT. The two would subsequently have a match on the April 6 NXT, which was won by Crews.
On April 4, 2016, Crews made his main roster debut on Raw, defeating Tyler Breeze. Crews then entered a feud with the Social Outcasts (Heath Slater, Curtis Axel, Bo Dallas and Adam Rose), defeating each member of the stable, culminating in a match on the April 18 Raw. Prior to the match, Crews agreed to join the Social Outcasts if any member of the stable could defeat him. As part of the agreement, the Social Outcasts also agreed to leave Crews alone if he won the match. Crews defeated Slater to end the feud. Crews suffered his first loss on the main roster on the May 23 Raw, losing to Chris Jericho in a Money in the Bank qualifying match. The loss was blamed on Sheamus' pre-match attack on Crews, starting a feud between the two. Crews and Sheamus faced off at Money in the Bank, where Crews was victorious.
On July 19, Crews was drafted to the SmackDown brand in the 2016 WWE draft. On the July 26 SmackDown, Crews won a battle royal to earn a spot in a six-pack challenge to determine the #1 contender to Dean Ambrose's WWE World Championship at SummerSlam. Later that same episode, Crews was defeated by Dolph Ziggler in the six-pack challenge, which also included AJ Styles, Baron Corbin, Bray Wyatt and John Cena. The following week, Crews defeated Corbin and Kalisto to become the #1 contender to the WWE Intercontinental Championship. Crews received his title shot on August 21 at SummerSlam, but was defeated by The Miz. Crews defeated The Miz in a non-title match at the 2016 Tribute to the Troops, which led to a title match on the December 20 SmackDown, where The Miz retained his title. On January 29, 2017, at the Royal Rumble, Crews took part in his first Royal Rumble match, entering as number 22 and being eliminated by Luke Harper. In early 2017, Crews teamed up with Kalisto to feud with Dolph Ziggler after Ziggler attacked Kalisto. At Elimination Chamber, Crews and Kalisto defeated Ziggler in a two-on-one handicap match. Following the match, Ziggler attacked the two, injuring Crews' ankle, which was trapped in a chair. This led to a chairs match on the February 28 SmackDown, where Ziggler was victorious.
On April 10, 2017, Crews was moved to the Raw brand as part of the Superstar Shake-up. Shortly thereafter, a storyline began with Titus O'Neil offering Crews his managerial services. After becoming affiliated with "The Titus Brand", Crews started displaying attitude and cockiness, most notably by mocking and attacking Enzo Amore on the May 15 episode of Raw. The following week, Kalisto confronted Crews about his alliance with "The Titus Brand", resulting in a match between the two, which Crews lost. On the Extreme Rules kickoff show, Crews was defeated by Kalisto. During that period, Akira Tozawa joined the Titus Brand, turning it into "Titus Worldwide". Crews would then enter a short feud with Elias, where Crews lost to Elias on the No Mercy kickoff show, the following night and October 9 episodes of Raw. On November 27, Dana Brooke also joined Titus Worldwide.
Brooke made her first official appearance with the team on the January 1, 2018, episode of Raw accompanying Crews along with O'Neil in a match against Bray Wyatt, in which he was defeated; at this point Tozawa quietly left the team. On the January 8 and January 15, 2018 episodes of Raw, Crews and O'Neil would defeat Cesaro and Sheamus in upset victories. At the Royal Rumble, Crews entered the Royal Rumble as the thirteenth entrant, being eliminated by Cesaro. On the January 29 episode of Raw, Crews and O'Neil competed in a match against Cesaro and Sheamus for the Raw Tag Team Championships, in a losing effort. On February 19, 2018, his ring name was shortened to Apollo. On the February 19 episode of Raw, Apollo and O'Neil defeated Cesaro and Sheamus in a non-title tag team rematch to earn another shot at the Raw Tag Team Championship. On February 25 at Elimination Chamber, Apollo and O'Neil lost their title match against Cesaro and Sheamus. The following night on the February 26 episode of Raw, Apollo and O’Neil competed in a 2 out of 3 falls match for the championships against Cesaro and Sheamus, losing 2–0 to end the feud.
On April 8 at WrestleMania 34, Apollo competed in the 2018 André the Giant Memorial Battle Royal in which he was unsuccessful. On the April 16 episode of Raw, he reverted to his full ring name Apollo Crews before he and O'Neil were attacked by Dolph Ziggler and Drew McIntyre. On the April 23 episode of Raw, Crews and O'Neil were defeated by Ziggler and McIntyre. On April 27 at the Greatest Royal Rumble, Crews entered at number 33 during the Royal Rumble match, in which he eliminated Chad Gable before eliminated by Randy Orton. On September 3, Dana Brooke parted ways with Titus Worldwide after a mid-match coaching backfired, causing Brooke and Ember Moon to lose to Bayley and Sasha Banks.
On the October 15 episode of Raw, Crews returned as a singles competitor when he interrupted Elias during his performance, thus disbanding Titus Worldwide. The following week, he lost to Elias. On the December 31 episode of Raw, Crews won a battle royal by eliminating eight wrestlers to become the number one contender for the Intercontinental Championship against Dean Ambrose. That same night, he was defeated by Ambrose. He competed in his third Royal Rumble match at the namesake pay-per-view on January 27, 2019, where he was eliminated by Baron Corbin. At WrestleMania 35, Crews competed in his third consecutive André the Giant Memorial Battle Royal but was eliminated by Andrade. On the April 16th episode of SmackDown, Crews was drafted back to the SmackDown brand during the 2019 Superstar Shake-Up. In June he started feuding with Andrade on SmackDown. Crews was eliminated by Andrade in the 50-Man Battle Royal at WWE Super Showdown. At the following NXT tapings, Crews made a surprise appearance to wrestle Kushida.
Crews faced Buddy Murphy during the SummerSlam Kickoff, however the match ended in disqualification after Rowan attacked Murphy. In early 2020, Crews turned heel for the first time in his career when he turned his back on friend Shorty G during their feud with the recently-returned Sheamus.
On the April 6, 2020 episode of Raw, Crews was traded to the brand, where he was defeated by Aleister Black in a highly competitive match, lasting up to 27 minutes. On the April 20 episode of Raw, Crews reverted back to his face status and defeated MVP to qualify for the Money in the Bank ladder match, however, the following week on Raw, he injured his knee in a United States Championship match against Andrade, thus ruling him out of Money in the Bank ladder match. On the May 18, 2020 episode of Raw, Crews returned in a tag team match with Kevin Owens, to defeat the team of Andrade and Angel Garza. On the May 25, 2020 edition of Raw, he defeated Andrade in a rematch to win the United States Championship, his first championship in WWE. At Backlash, Crews once again retained his championship against Andrade after an assist by Kevin Owens. On the June 15 episode of Raw, Crews was approached by MVP, who offered him his services stating that he could help him reach the top as United States Champion but Crews turned him down. Later on in the night, Crews defeated Shelton Benjamin by using the ropes as leverage, teasing a possible heel turn for Crews. The following week on Raw, Crews was a guest on MVP's VIP Lounge, who once again offered Crews his services but Crews insisted that he didn't need MVP nor did he need him to win the United States Championship. Crews was then attacked by Benjamin before their scheduled match but managed to defeat Benjamin. After the match, Crews was attacked by MVP's client Bobby Lashley, who put him in his full nelson hold. This set up a United States Championship match between Crews and MVP at The Horror Show at Extreme Rules; however, Crews was absent at the event, with MVP unofficially declaring himself the new United States Champion. On the August 3 episode of Raw, Crews returned and retained the United States Title against MVP. At SummerSlam, Crews once again defeated MVP to retain the title. At Payback the next week, Crews lost his title to Bobby Lashley, ending his reign at 97 days. At Clash of Champions, Crews failed to regain the title from Lashley.
As part of the 2020 draft in October, Crews was drafted back to the SmackDown brand. On the December 25 episode of SmackDown (taped on December 22), Crews was part of the lumberjacks for Big E's championship match against Intercontinental Champion Sami Zayn, where Crews chased Zayn down when the latter attempted to escape, and Big E ultimately captured the title. The following week, Crews saved Big E from a double assault from Zayn and King Corbin, and subsequently, they defeated Zayn and Corbin in a tag team match. On the January 8, 2021 episode of SmackDown, Crews faced Big E for the title, where the match ended in a double-pinfall, and after the match, Crews hinted at a heel turn when he slapped Big E while asking for an immediate rematch, where Crews was subsequently defeated.
The next day on Talking Smack, Crews was interviewed by Paul Heyman, who commented on Crews's attempts to win the title and also commenting on his "nice guy" persona holding him back. On the January 15 episode of SmackDown, Crews was seen backstage talking with Universal Champion Roman Reigns, where Reigns was giving Crews advice on his career. On the February 12 episode of SmackDown, Crews interfered the match between Big E and Shinsuke Nakamura and attacked Big E, thus turning heel for the first in his WWE career. The following week, after losing to Nakamura, Crews attacked Nakamura and Big E again, confirming his turn.
Crews would then debut a new character where he declared himself Nigerian royalty, began to speak with a Nigerian accent in his promos in order to "embrace who he really is" and began coming to the ring with a spear. Crews failed to win the Intercontinental Championship at Fastlane. On the April 2 episode of SmackDown, Crews would challenge Big E at WrestleMania 37 in a Nigerian Drum Fight for the Intercontinental Championship, and Big E would accept. At WrestleMania 37, he defeated Big E with the help of his new confidant Commander Azeez to win the Intercontinental Championship. Crews then successfully retained his title against Kevin Owens on the April 23 episode of SmackDown, against Owens, Big E, and Sami Zayn in a fatal four-way match on the May 21 episode of SmackDown, and against Owens again on the June 4 episode of SmackDown. On the August 13 episode of SmackDown, Crews dropped the title to King Nakamura, ending his reign at 125 days. As part of the 2021 Draft, both Crews and Azeez were drafted to the Raw brand.
In June 2022, Crews returned to NXT, making his return on the June 7 episode as a face, dropping his Nigerian accent and confronting NXT Champion Bron Breakker. He would make his in-ring return for the brand on the same night, teaming up with Solo Sikoa to take on Carmelo Hayes and Grayson Waller, which they would go on to win. On December 10 at NXT Deadline, Crews challenged Breakker for the NXT Championship in a losing effort. Soon after, Crews would engage in a feud with Carmelo Hayes, leading to a two-out-of-three falls match at NXT Vengeance Day, where Crews lost to Hayes in two straight falls. After the match, Crews would be attacked by his former ally Dabba-Kato, who was originally Commander Azeez. This resulted in a match on the March 14 episode of NXT, where Crews was defeated.
As part of the 2023 WWE Draft, Crews was drafted back to the Raw brand. On the May 22 episode of Raw, Crews began a short feud with the The Judgment Day, turning face in the process. Later in the night, Crews lost to Dominik Mysterio. After a seven-month hiatus, Crews returned on the March 4, 2024 episode of Raw, losing to a returning Andrade. Crews was drafted to the SmackDown brand on night two of the 2024 WWE Draft on April 29. On the June 14 episode of SmackDown, Crews would begin a feud with Legado del Fantasma after they interfered in his match against Andrade and would begin teaming regularly with Baron Corbin.