It was announced on 16 February 2010 that Wade Barrett would be competing on the first season of WWE NXT, with Chris Jericho as his storyline mentor. His first appearance for NXT was on the inaugural episode of NXT on 23 February, when he acted as Jericho's ring announcer. Barrett made his in-ring debut on the following episode of NXT, defeating Daniel Bryan. On the 13 April episode of NXT, Barrett won the "talk the talk" challenge and was awarded his own custom made entrance theme. On 11 May, Barrett was ranked in first place in the Pros Poll. On the 1 June episode of NXT, Barrett won the overall competition, and a WWE contract, by defeating David Otunga and Justin Gabriel in the season finale.
On the 7 June episode of WWE Raw, Barrett was at the forefront of an attack by the NXT rookies, as they interfered in the main event match between John Cena and CM Punk, attacking both competitors, the Straight Edge Society, the announce team, the timekeeper and the ring announcer, before they destroyed the ring area and surrounding equipment. Cena in particular was heavily targeted by the rookies, who hit him with their finishing moves. On the next episode of Raw, Barrett and the other rookies (minus Daniel Bryan) demanded full-time contracts from Raw General Manager Bret Hart, who instead fired Barrett and had the rookies removed from the building. Later in the show the rookies attacked Hart and gave him until the Fatal 4-Way pay-per-view to decide on their contracts. At Fatal 4-Way, the rookies interfered in the main event for the WWE Championship, costing John Cena the championship in the process. The following night on Raw, Vince McMahon fired Hart and announced that a new 'anonymous' General Manager had been hired and the seven rookies received WWE contracts. The group of rookies continued their path of disrupting main events, as they attacked both Cena and McMahon, who had been acting as the referee. The following week, the group was named The Nexus. That same week, Barrett was absent on Raw as his work visa had expired and he had had to return to the United Kingdom to apply for a new one. With his visa situation cleared up, Barrett returned the following week. On the 12 July episode of Raw, the Nexus, sans Darren Young, competed in their first match together and defeated John Cena in a six–on–one handicap match. The following week, Barrett made his singles match debut on Raw by defeating Mark Henry. The Nexus continued to feud with Cena and the Raw roster, resulting in a seven-on-seven elimination tag team match at SummerSlam. Barrett was the final member of the Nexus but submitted to Cena, causing the Nexus to lose the match. After Darren Young was exiled from the group and Skip Sheffield was injured, the Nexus faced Cena, Edge, Randy Orton, Sheamus and Jericho in a five-on-five elimination match on the 900th episode of Raw on 30 August. Barrett won the match for his team by last eliminating Orton.
Barrett received his guaranteed championship match from winning NXT at Night of Champions, where he was unsuccessful in a six-pack challenge match for the WWE Championship, despite eliminating Cena. The feud between Cena and the Nexus continued at Hell in a Cell on 3 October, when Barrett defeated Cena to force Cena to become a member of the Nexus. The following night on Raw, Barrett, with the help of the rest of the Nexus, won a battle royal to determine the number one contender to the WWE Championship, when Cena eliminated himself on Barrett's orders. Barrett received his championship match against Randy Orton at the Bragging Rights pay-per-view. After ordering Cena to help him win, Cena interfered in the match causing Barrett to win via disqualification, which meant that Orton retained the championship. The following night, Barrett was granted a rematch at the Survivor Series pay-per-view, and allowed to choose a guest referee. He chose Cena, stating that if Barrett won the match and the WWE Title, Cena would be allowed to leave the Nexus, but if Barrett failed to win the title, Cena would be fired. At Survivor Series, Barrett was unsuccessful in winning the WWE Championship from Orton after Cena pushed him into an RKO by Orton. Cena was fired as per the match stipulation after Survivor Series.
Due to Cena's interference, Barrett received a rematch for the championship the following night on Raw, but was attacked by the fired Cena, costing him the match. After Cena attacked several members of the Nexus over the next few weeks, they demanded that Barrett re-instate him, or be exiled from the group. On the 13 December episode of Raw, Barrett agreed and rehired Cena. As a condition of his rehiring, Cena had to face Barrett in a Chairs match at the TLC: Tables, Ladders & Chairs pay-per-view, which Barrett lost.
Barrett made his first appearance since the TLC pay-per-view on the 3 January 2011 episode of Raw, where he confronted CM Punk, who had taken over the leadership of the Nexus in his absence. Punk gave Barrett the opportunity to regain the leadership, stating that if he won a three-way steel cage match involving Orton, Sheamus and Barrett to determine the number one contender for the WWE Championship, Punk would not only give up the leadership, but work for Barrett's Nexus. However, during the match, Punk came down to ringside, attacked Barrett as he was about to win and took off Barrett's Nexus armband, symbolically removing him from the Nexus. Barrett went on to lose the match.
At the television tapings of the 7 January episode of SmackDown the next day, Barrett made his SmackDown debut by attacking The Big Show. The following week he was joined by Ezekiel Jackson and his former Nexus stablemates Justin Gabriel and Heath Slater, who had left the group the previous Monday, the group named themselves as the Corre. Barrett later qualified for the WWE Elimination Chamber match for the World Heavyweight Championship, but came up short after being the first man eliminated by The Big Show. On 22 March, at the tapings of the 25 March episode of SmackDown, Barrett defeated Kofi Kingston to win the WWE Intercontinental Championship. At WrestleMania XXVII, The Corre were defeated in an eight-man tag team match by the team of Kingston, The Big Show, Kane, and Santino Marella. Barrett went on to successfully defend his championship against Kingston on the 22 April episode of SmackDown. On the 6 May episode of SmackDown, Barrett, Gabriel, and Slater attacked Jackson, removing him from the group. On the 13 May episode of SmackDown, Barrett then challenged Jackson to a match for the Intercontinental Championship at the Over the Limit pay-per-view, and Jackson accepted. At the event, Gabriel and Slater attacked Jackson during the match, causing Barrett to lose by disqualification, but Barrett retained his Intercontinental Championship. He would then have to defend his Intercontinental Title against Jackson again on the 3 June episode of SmackDown. During the match, Jackson threw Barrett out of the ring, resulting in Barrett losing by countout, but Barrett still retained his Intercontinental Title as a title cannot change hands via countout. Barrett then instructed the Corre to attack Jackson, but then abandoned Gabriel and Slater, whom Jackson fended off. On the 10 June episode of SmackDown, The Corre dissolved after Barrett, fleeing from Jackson, walked out on Gabriel and Slater in a 6-man tag team match against Jackson and The Usos, causing them to lose the match.
At WWE Capitol Punishment, Barrett lost the Intercontinental Championship to Jackson. He invoked his rematch clause against Ezekiel Jackson for the Intercontinental Champion on the 24 June episode of SmackDown, but lost. On the 1 July episode of SmackDown, Barrett was announced to be one of the participants for the SmackDown Money in the Bank match at the Money in the Bank pay-per-view, facing Heath Slater, Justin Gabriel, Kane, Sin Cara, Daniel Bryan, Cody Rhodes and Sheamus, which was won by Bryan. On the 22 July episode of SmackDown, Barrett faced Sheamus and both men were counted out. The following week Wade Barrett came to talk about how he was deserved to be Mr. Money in the Bank, Daniel Bryan came out and put him in the LeBell Lock. The following week, he was at commentary during Bryan's match. On the following SmackDown, Barrett attacked Bryan after the latter's loss to Alberto Del Rio. At SummerSlam, Barrett defeated Bryan in a singles match. He then had a short feud with Sheamus, where he lost on three occasions. On September 23 episode of Smackdown, Barrett defeated another former Nexus and Corre teammate, Justin Gabriel.
On the October 21 episode of SmackDown held in Mexico, Barrett dismissed his past alliances with a "legion of parasites", claiming that the only person he needed for him to succeed was himself, and he vowed that the "Barrett Barrage" was beginning. Barrett followed this announcement by beating Daniel Bryan. The next week, he would obtain wins over John Morrison on Raw and Trent Barreta on SmackDown. Barrett's winning streak continued as he and Cody Rhodes defeated the WWE Tag Team Champions Air Boom (Evan Bourne and Kofi Kingston) on the October 31 episode of Raw and the November 4 episode of SmackDown when he defeated Sheamus, following interference from Christian.
The following week, after being announced as the Team Captain for the Survivor Series match against Team Orton, Barrett defeated Randy Orton. Barrett's winning streak was broken on the November 14 episode of Raw, when he was defeated by Orton via disqualification after Team Barrett attacked Orton. At Survivor Series, Team Barrett defeated Team Orton, with Barrett and Cody Rhodes being the sole survivors in the match. On the November 25 episode of SmackDown, Barrett competed in a Fatal-4-Way match against Orton, Rhodes and Daniel Bryan to determine the #1 Contender for the World Heavyweight Championship which Bryan won. Barrett would continue his feud with Orton by attacking and distracting him during matches. On the December 9 episode of SmackDown, Barrett and Orton were put in two Beat the Clock Challenge matches, with the winner choosing the stipulation for their match at TLC: Tables, Ladders & Chairs. Barrett defeated Ezekiel Jackson in 7:53, however, Orton pinned Dolph Ziggler in 7:51 and chose a Tables match. At Tables, Ladders, and Chairs, Orton defeated Barrett after hitting the RKO mid-air with Barrett landing through the table. Barrett and Orton would continue their feud on the December 23 episode of SmackDown, where they engaged in a brawl that ended backstage with Barrett getting hit with a RKO onto a car. This led to a Falls Count Anywhere match on December 30 episode of SmackDown, where Barrett pushed Orton down a set of stairs before exiting through the door. Orton suffered a herniated disc as a result, taking him off television for a number of weeks. After Orton returned from injury in late January 2012, he eliminated Barrett from the 2012 Royal Rumble match. On the February 3 edition of SmackDown, Orton defeated Barrett in a No Disqualifications match to end the feud.
At Elimination Chamber, Barrett failed to capture the World Heavyweight Championship after being eliminated fourth by Santino Marella. On the February 20 episode of Raw, Barrett suffered an partially dislocated elbow after Big Show threw Dolph Ziggler onto Barrett during a 10-man battle royal, and was thus taken off television.
In August 2012, WWE aired vignettes promoting Barrett's return, showing Barrett fighting at an underground fight club in an attempt to "reignite the flame". Barrett made his return on the September 7 episode of SmackDown, quickly defeating Yoshi Tatsu in a squash match. Following his return, Barrett would go on an undefeated streak, defeating the likes of Justin Gabriel, Tyson Kidd, and various other competitors. Barrett suffered his first defeat since his return to the WWE in a Lumberjack Match against the World Heavyweight Champion Sheamus. On November 18 at Survivor Series, Barrett was part of the winning team of Dolph Ziggler against the team of Mick Foley, where he eliminated Intercontinental Champion Kofi Kingston before being eliminated by The Miz. The following night on Raw, Barrett defeated Kingston in a non-title match to earn a shot at the Intercontinental Championship. Barrett, still number one contender, received a shot at the United States Championship on the December 3 episode of Raw, against champion Antonio Cesaro, Kofi Kingston, and R-Truth in a fatal four-way match, but was unsuccessful. On December 16 at TLC: Tables, Ladders & Chairs, Barrett failed to win the Intercontinental Championship from Kingston. During the December 31, 2012 episode of Raw, Barrett defeated Kingston to win the Intercontinental Champion for the second time. Barrett made his first successful title defense four days later on SmackDown, defeating Kingston in a rematch. Barrett entered the 2013 Royal Rumble match and was eliminated by the debuting Bo Dallas, but Barrett later returned to eliminate Dallas as well. This started a feud between the duo, with Barrett challenging Dallas to a non-title match the next night on Raw, and Dallas pulling off an upset victory. On the February 1st 2013 edition of Smackdown, after his loss to Randy Orton, he would vent out his frustration and attack Dallas backstage. On the March 18 episode of Raw, Barrett defeated Chris Jericho and The Miz in a three-way match to retain the Intercontinental Championship. On 7 April, during the Wrestlemania 29 pre-show, Barrett lost the Intercontinental Championship to The Miz, ending his reign at 99 days. He would, however, win the title back from Miz the next night on Raw. On the April 17 episode of Main Event, Barrett successfully defended his title against his former Nexus and Corre friend Justin Gabriel. On the May 20 episode of Raw, Barrett and Fandango were defeated by Chris Jericho and The Miz in a tag team match after Fandango left the match to dance at ringside and Miz submitted Barrett with the Figure-Four Leglock. Four days later on SmackDown, Barrett warned Fandango to never cross his path again or there would be trouble. Barrett would then lose an Intercontinental Championship match to The Miz via disqualification after Fandango interfered, leading to Barrett attacking Miz and Fandango post-match. He would on to lose the championship to new contender Curtis Axel at the Payback pay-per-view. Barrett received his rematch for the title on the following episode of SmackDown, but was again defeated by Axel. On July 14 at the Money in the Bank pay-per-view, Barrett competed in the World Heavyweight Championship Money in the Bank ladder match, but was unsuccessful as the match was won by Damien Sandow. Barrett finally ended his long losing streak on the July 31 episode of Main Event, when he defeated R-Truth. On the August 5 episode of Raw, Barrett was to shave Daniel Bryan's beard at the orders of Vince McMahon as part of Bryan's "corporate makeover"; as Barrett was about to shave Bryan, Bryan blindsided Barrett and shaved off his beard. That same week on SmackDown, Barrett, now clean shaven, faced off against Bryan in singles competition, but was defeated after submitting to the Yes! Lock. In a rematch on the next episode of Raw, Barrett defeated Bryan after special guest referee Brad Maddox made a fast count on Bryan. Four days later on SmackDown, Barrett was again defeated by Bryan in a no disqualification match after COO Triple H thwarted the attempts of interference from McMahon and Maddox and counted the pinfall victory for Bryan.
Despite being absent from WWE television, Barrett frequently appeared on the JBL and Cole Show on WWE's YouTube channel, giving bad news to other WWE Superstars and Divas. Wade Barrett returned on November 7 at a WWE live event in Dublin and called himself "Bad News Barrett". He cut a heel promo on Ireland before defeating Zack Ryder. He returned to TV on the December 2 episode of Raw, under his Bad News Barrett persona. On the January 15th edition of Main Event, Barrett announced that he would participate in the 2014 Royal Rumble Match, but was later taken off for unclarified reasons. On the 17 February episode of Raw, he appeared in a backstage segment with Cody Rhodes and Goldust, where he kicked a collection of wrestler figurines off the table when Rhodes and Goldust were playing with them. At the 2014 Elimination Chamber PPV, he appeared multiple times after some matches. He returned to the ring on April 7, 2014, defeating Rey Mysterio. He continued his successful return on the April 11 edition of SmackDown with a win over Kofi Kingston. On the 14 April episode of Raw, Barrett defeated Dolph Ziggler to in round one of the #1 Contender's Tournament for an Intercontinental Championship match at Extreme Rules and on the 21 April Raw, Barrett defeated Sheamus to advance to the finals of the tournament. Barrett defeated Rob Van Dam on the 28 April Raw in the final round of the tournament, Barrett's win earned him a match at Extreme Rules for the Intercontinental Championship against Big E, where he became the Intercontinental Champion for the fourth time in his career. He beat Big E the following night in a rematch on Raw, retaining the title. He then defeated Rob Van Dam at Payback 2014 to retain the title. On the June 9 edition of Raw, he competed for a WWE World Heavyweight Championship Ladder Match spot for Money in the Bank 2014 but failed after a Brogue Kick by Sheamus. However, Triple H put him in the Money in the Bank Ladder Match for a WWE World Heavyweight Championship contract on the 23 June Raw. The following night at the SmackDown tapings, Barrett separated his shoulder after he was thrown into the barricade by Jack Swagger, so he was pulled from the pay-per-view as a result. On the June 30 edition of Raw, Michael Cole announced that Barrett's injury will require surgery and he will be forced out of action for a number of months, effectively stripping him of the Intercontinental Championship. After a five month absence, he returned in November at Survivor Series, in a segment on the pre-show. He returned to action on the 29 December edition of Raw, defeating Cesaro. He captured his fifth Intercontinental Championship the following week on Raw when he defeated Dolph Ziggler in a 2-out-of-3 falls match.
At Fastlane, Barrett retained his title against Dean Ambrose after Ambrose got himself disqualified. Ambrose then stole the Intercontinental title belt, but he would not be the only one to do so for the following weeks, as various wrestlers gained possession of Barrett's title belt, including R-Truth, Luke Harper, Dolph Ziggler, Daniel Bryan and Stardust. Of these people, Barrett was pinned in non-title matches against R-Truth, Ziggler, Bryan and Ambrose within a month before and after Fastlane. Thus, a ladder match for the Intercontinental title was made for WrestleMania 31 for Barrett against Ambrose, Harper, R-Truth, Ziggler, Stardust and Bryan. Bryan ultimately won the match. Barrett was scheduled to face Bryan for the championship in a rematch at Extreme Rules, however Bryan was not medically cleared to compete. Barrett instead faced Neville in a losing effort on the pre–show.
On the 28 April episode of Raw, Barrett would compete on the 2015 King of the Ring tournament, where he defeated Dolph Ziggler in the first round after Ziggler was distracted by Sheamus. The following night on the WWE Network, Barrett would defeat R-Truth in the semi-finals before defeating fellow Englishman Neville in the final to win the tournament, making him the twentieth winner of the tournament. Barrett's ring name was officially changed to King Barrett shortly after winning the tournament. He would go on to deliberately get himself counted-out to Neville at Payback. King Barrett participated in the Elimination Chamber match for the vacant Intercontinental Championship, but was the first eliminated by R-Truth. Barrett would go on to lose to Truth on the Money in the Bank Kickoff Show. After his victory, Truth began referring to himself as "King What's up" and wore a cape and crown to mock King Barrett. The renewed feud accumulated to Battleground, which saw Barrett defeat Truth. Had Truth won, Barrett would have given up his status as "King". On the August 10th episode of Raw, it was announced that Barrett would team up with Stardust to take on Neville and Stephen Amell at SummerSlam. At the event, they were defeated when Neville performed the Red Arrow on Barrett for the win. The night after SummerSlam, Stardust turned on Barrett for costing him the match, disbanding their tag team.
On the September 28 episode of Raw, Barrett returned to television attacking Neville and Stardust, the latter of which Barrett explained was his intended target when he joined the Raw commentary team. On the October 5, 2015 edition of Raw during Neville's match with Sheamus, Barrett inadvertently distracted Neville long enough for Sheamus to connect with the Brogue Kick for the win. He then formed a tag team with Sheamus and they defeated Neville and Cesaro in tag team matches both on Raw and SmackDown the following week. At the November 9 episode of Raw, during Sheamus' match with Cesaro, Barrett got in a confrontation with soccer player, Wayne Rooney, which led to Rooney slapping Barrett. On the November 12 SmackDown episode, after losing to Neville in the WWE World Heavyweight Title Tournament's first round, he would also be confronted by The Undertaker, who proceeded to give Barrett a chokeslam and two Tombstone Piledrivers. arrett later took part in a traditional 5-on-5 elimination match the following Sunday at Survivor Series (2015) alongside Sheamus and the The New Day against Ryback, The Usos, and The Lucha Dragons. Barrett was the first eliminated by Sin Cara. His team would later lose that night. On the following edition of Raw, Barrett arrived to aid Rusev and WWE World Heavyweight Champion Sheamus against Roman Reigns, thus aligning himself with the Authority and reforming the European trio. On the November 30 episode of Raw, after interfering in Sheamus' title defense against Reigns, Sheamus announced the formation of The League of Nations stable alongside Barrett, Rusev and Alberto Del Rio. However, Barrett injured his arm in December 2015. He would return to action in February of 2016 on an episode of SmackDown.
On the March 7, 2016 episode of Raw, Barrett made his Raw in-ring return, teaming with Sheamus and Rusev in a 3-on-1 Handicap Elimination match against Dolph Ziggler. The League of Nations would get the win, with Barrett being the only one eliminated. At Roadblock, Barrett and Sheamus unsuccessfully challenged The New Day for the WWE Tag Team Championship. On the 14 March edition of Monday Night Raw, Barrett and the entire League of Nations attacked the New Day, after Alberto Del Rio lost to Big E and Xavier Woods in a Tag Team title match. After the attack, Sheamus issued a challenge to The New Day for a 4-on-3 match at WrestleMania 32. On 17 March episode of Smackdown, Barrett suffered a loss against Kofi Kingston. At WrestleMania, Barrett and his stablemates defeated The New Day. On the 4 April episode of Raw, Barrett and Sheamus faced The New Day in another tag team title match, in a losing effort. After the match, the League of Nations blamed Barrett for being the "weak link" and attacked him, ejecting him from the group, before the rest of the team was attacked by The Wyatt Family. This was used to write Barrett off television, and he was granted an early release from his contract, due to expire in June, on May 6th.