Ambrose, as Jon Moxley, made three appearances in World Wrestling Entertainment (WWE) from 2006 to 2007, on Heat and Velocity, all of which resulted in losses.
On November 18, 2012, Ambrose made his WWE main roster debut at the Survivor Series pay-per-view event alongside Roman Reigns and Seth Rollins, as they delivered a triple powerbomb through an announce table to Ryback during the triple threat main event for the WWE Championship, allowing CM Punk to pin John Cena and retain the title. The trio declared themselves The Shield, and vowed to rally against "injustice" and denied working for Punk, but they routinely emerged from the crowd to attack Punk's adversaries, including Ryback and the WWE Tag Team Champions Team Hell No (Daniel Bryan and Kane), establishing themselves as villains. This led to a six-man Tables, Ladders, and Chairs match being set up for the TLC pay-per-view event on December 16, where Ambrose, Rollins, and Reigns defeated Ryback and Team Hell No in their debut match. The Shield continued to aid Punk after TLC, both on Raw and at the Royal Rumble in January 2013. The night after the Royal Rumble, it was revealed through footage that Punk and his manager Paul Heyman had been paying The Shield to work for them all along. The Shield then quietly ended their association with Punk. At Elimination Chamber in February, The Shield defeated Ryback, John Cena and Sheamus. At WrestleMania 29 in April, The Shield won their first WrestleMania match against Sheamus, Randy Orton and Big Show. Ambrose made his singles debut against The Undertaker on the April 26 episode of SmackDown, which he lost by submission. On the May 13 episode of Raw, The Shield's undefeated streak as a team ended in a disqualification loss against WWE Champion John Cena and Team Hell No.
At Extreme Rules, Ambrose won the United States Championship by defeating Kofi Kingston. He would successfully defend the title in the following weeks with the help of Reigns and Rollins. On the June 14 episode of SmackDown, The Shield was given their first decisive loss, against Randy Orton and Team Hell No, when Daniel Bryan made Rollins submit. Two days later, Ambrose made his first pay-per-view defense of the United States Championship at Payback, where he defeated Kane by countout. The following month at Money in the Bank, he competed in the World Heavyweight Championship Money in the Bank ladder match, but failed to win despite interference from Reigns and Rollins. In August, The Shield allied themselves with Triple H and joined his group, The Authority.
Ambrose continued to retain his United States Championship against Rob Van Dam at SummerSlam, Dolph Ziggler at Night of Champions, and Big E Langston at Hell in a Cell. At the Survivor Series pay-per-view, The Shield teamed with Antonio Cesaro and Jack Swagger to take on Rey Mysterio, The Usos, Cody Rhodes and Goldust in a traditional Survivor Series match; although Ambrose was the first man eliminated, Reigns would ultimately win the match for the team. At TLC in December, CM Punk defeated The Shield in a handicap match after Ambrose was accidentally speared by Reigns. At the Royal Rumble on January 26, 2014, Ambrose entered his first Royal Rumble match at number 11 and eliminated three participants, before being eliminated by Reigns. The following night on Raw, The Shield faced Daniel Bryan, John Cena, and Sheamus in order to earn their spot in the Elimination Chamber match for the WWE World Heavyweight Championship. The Shield lost after The Wyatt Family (Bray Wyatt, Erick Rowan, and Luke Harper) interfered, thus starting a feud between the two factions. The Shield would lose to The Wyatt Family at the Elimination Chamber pay-per-view, due to Ambrose abandoning the match midway through.
After their feud with The Wyatt Family, The Shield moved on to a rivalry with Kane, turning into heroic characters in the process. The group defeated Kane and The New Age Outlaws (Road Dogg and Billy Gunn) at WrestleMania XXX on April 6. The feud with Kane also prompted The Shield to cease working for Triple H, who reformed Evolution with himself, Batista and Randy Orton to battle them. On April 28, Ambrose surpassed MVP as the longest-reigning United States Champion under the WWE banner. The Shield defeated Evolution in a six-man tag team match at Extreme Rules. The following night on Raw, Triple H forced Ambrose to defend his United States Championship in a 20-man battle royal, which saw Ambrose surviving until the final two before ultimately being eliminated by Sheamus, thus ending his title reign at 351 days. The Shield once again defeated Evolution at Payback in a No Holds Barred elimination match in June. The following night on Raw, Rollins betrayed Ambrose and Reigns and aligned himself with The Authority, breaking up the group.
Ambrose promptly began feuding with Rollins, which included the duo interfering in each other's matches. During this period, Ambrose and Reigns amicably separated as a team, with Ambrose debuting new ring attire and new entrance music. Ambrose competed the 2014 Money in the Bank ladder match on June 29, which Rollins would win after Kane attacked Ambrose. Ambrose was scheduled to face Rollins at Battleground on July 20, but he was ejected from the arena by Triple H after a pre-match brawl with Rollins. Rollins was later announced as the winner via forfeit, prompting Ambrose to return to the arena and attack Rollins. Ambrose and Rollins eventually wrestled at SummerSlam on August 17 in a lumberjack match, which Ambrose lost after Kane again interfered and Rollins hit Ambrose with his Money in the Bank briefcase. The following night on Raw, Ambrose faced Rollins in a Falls Count Anywhere match, which Ambrose lost by knockout after interference from Kane once again. After the match, Rollins curb stomped his head through cinder blocks, giving Ambrose kayfabe "head and spine trauma" and causing him to take a hiatus from WWE. Ambrose returned at Night of Champions in September and attacked Rollins. The duo faced off in a Hell in a Cell match the following month at the namesake event, where Ambrose lost again when the returning Bray Wyatt interfered and attacked him.
Ambrose lost to Wyatt at both the Survivor Series and TLC pay-per-views. The two met for a third time in a Miracle on 34th Street Fight on the December 22 episode of Raw, which Ambrose again lost. The feud between the two concluded when Wyatt defeated Ambrose in an ambulance match on the January 5, 2015 episode of Raw. At the Royal Rumble on January 25, Ambrose participated in the Royal Rumble match, but was eliminated by Big Show and Kane. Ambrose then began a feud with Intercontinental Champion Bad News Barrett. He failed to win the championship from Barrett at Fastlane and WrestleMania 31. Ambrose defeated Luke Harper at Extreme Rules in a Chicago Street Fight on April 26, his first singles victory on a pay-per-view event since The Shield split up. The following night on Raw, Ambrose competed in the 2015 King of the Ring tournament, but was disqualified from the competition during his quarterfinal match with Sheamus, after interference from Dolph Ziggler.
Ambrose returned to feud with Rollins over the WWE World Heavyweight Championship, defeating him in a non-title match on the May 4 episode of Raw. As a result of this, he was added to Rollins's championship defense at Payback against Randy Orton and Roman Reigns. Rollins would retain his championship. At Elimination Chamber on May 31, Ambrose faced Rollins in a singles match for the championship. He won the match by disqualification after Rollins shoved the referee, but did not win the title, as championships cannot change hands by disqualification. Regardless, Ambrose stole the championship belt from him and challenged Rollins to a ladder match for the title at Money in the Bank on June 14, which he narrowly lost.
After Money in the Bank, Ambrose teamed up with Roman Reigns to defeat Wyatt and Harper at SummerSlam. The following night on Raw, Ambrose and Reigns fought Wyatt and Harper in a SummerSlam rematch, during which Braun Strowman made his WWE debut, helping Harper and Wyatt. At Night of Champions on September 20, Ambrose, Reigns and a returning Chris Jericho were defeated by Wyatt, Harper, and Strowman in a six-man tag team match. After Rollins legitimately injured his knee on November 3, the WWE World Heavyweight Championship was declared vacant; Ambrose entered a 16-man tournament to determine a new champion. After defeating Tyler Breeze in the first round, Dolph Ziggler in the quarterfinals, and Kevin Owens in the semifinals, Ambrose ultimately made it to the finals at the Survivor Series main event on November 22 but lost to Reigns.
In December, Ambrose won the Intercontinental Championship for the first time after defeating Owens at TLC. He successfully defended the title against Owens and Ziggler multiple times between December and January 2016. Ambrose competed in the 2016 Royal Rumble match for the WWE World Heavyweight Championship, which he lost after being lastly eliminated by eventual winner Triple H. Ambrose would later lose the Intercontinental Championship back to Owens in a five-way match on the February 15 episode of Raw, after Owens pinned Tyler Breeze.
At Fastlane on February 21, Ambrose faced Reigns and Brock Lesnar in a triple threat match to determine the number one contender for the WWE World Heavyweight Championship at WrestleMania 32, but lost after he was pinned by Reigns. The following night on Raw, Ambrose challenged Lesnar to a No Holds Barred street fight match at WrestleMania 32, which Paul Heyman accepted on Lesnar's behalf. He then failed to capture the WWE World Heavyweight Championship from Triple H at the Roadblock event in March. He was also unsuccessful in defeating Lesnar at WrestleMania 32. Following WrestleMania, Ambrose began a rivalry with Chris Jericho. He defeated Jericho at Payback, and again at Extreme Rules in an Asylum match later that month to end the feud.
In May, Ambrose qualified for the 2016 Money in the Bank ladder match, which he would win. Later that same night, he would cash in his Money in the Bank contract and defeat Rollins to win the WWE World Heavyweight Championship for the first time. Ambrose made his first title defense against Rollins on the July 18 episode of Raw, which ended in a draw after a double pinfall. The following night at the 2016 WWE draft, Ambrose was drafted to SmackDown, being the brand's first draft pick and bringing the WWE Championship with him; that same night, he pinned Rollins to retain the championship. At Battleground, Ambrose retained his title against Reigns and Rollins after pinning Reigns. Ambrose then successfully defended the renamed "WWE World Championship" against Dolph Ziggler at SummerSlam in August. At Backlash on September 11, he lost the title to AJ Styles after Styles performed a low blow and Styles Clash while the referee was incapacitated. Ambrose was unsuccessful in regaining the championship at No Mercy on October 9 in a triple threat match also involving John Cena, who was pinned by Styles. The following month at Survivor Series, Ambrose made up part of Team SmackDown alongside Styles, Bray Wyatt, Randy Orton and Shane McMahon in a winning effort over Team Raw. He would face Styles once again in a Tables, Ladders, and Chairs match at TLC for the WWE title. During the match, James Ellsworth interfered and pushed Ambrose off a ladder through multiple tables, allowing Styles to retain the title. Ambrose would then fail to become the number one contender for the reverted WWE Championship in a fatal four-way elimination match involving Dolph Ziggler, Luke Harper, and The Miz.
On the January 3, 2017 episode of SmackDown, Ambrose defeated The Miz to win the Intercontinental Championship for the second time. He participated in the 2017 Royal Rumble match in which he lasted almost 27 minutes before being eliminated by Brock Lesnar. On February 12, Ambrose took part in the WWE Championship Elimination Chamber match at the event of the same name, where he eliminated Baron Corbin with a roll-up pin only for Corbin to attack him afterward, allowing Miz to eliminate Ambrose. A match was set between Ambrose and Corbin on the WrestleMania 33 pre-show on April 2, where Ambrose retained his Intercontinental Championship. Two nights later on SmackDown, Ambrose wrestled in his final match for the brand, in a losing effort to Corbin in a non-title match. Following that, Ambrose was moved to the Raw brand as a result of the Superstar Shake-up. He would then continue his feud with The Miz, who was also drafted to the aforementioned brand in the Superstar Shake-up, eventually losing the Intercontinental title to him at Extreme Rules in June, thus ending his reign at 152 days. Ambrose continued to feud with The Miz, leading up to a rematch for the Intercontinental Championship at Great Balls of Fire on July 9, where he lost after interference by The Miztourage (Curtis Axel and Bo Dallas).
On the July 10 episode of Raw, Seth Rollins saved Ambrose from an attack by The Miz and The Miztourage. After failing to gain Ambrose's trust for several weeks, the two argued in the ring on the August 14 episode of Raw and eventually brawled with each other before fighting off Cesaro and Sheamus, reuniting the team in the process. At SummerSlam on August 20, Ambrose and Rollins defeated Cesaro and Sheamus to win the WWE Raw Tag Team Championship, making Ambrose both a Triple Crown and Grand Slam champion in the process. Ambrose and Rollins successfully defended the titles against Cesaro and Sheamus at No Mercy, after Ambrose pinned Sheamus.
On the October 9 episode of Raw, Ambrose and Rollins reunited with Roman Reigns. The newly reformed Shield was due to face the team of Braun Strowman, Cesaro, Kane, The Miz and Sheamus at TLC in a 5-on-3 handicap Tables, Ladders and Chairs match, but Reigns was replaced by Kurt Angle over an illness concern. Ambrose, Rollins, and Angle would go on to win the match. Ambrose and Rollins were scheduled to face SmackDown Tag Team Champions The Usos in an interbrand match at Survivor Series, but lost the tag titles back to Cesaro and Sheamus on the November 6 episode of Raw after a distraction from SmackDown's The New Day (Big E, Kofi Kingston, and Xavier Woods), thus ending their reign at 78 days. This led to a match between The Shield and The New Day at Survivor Series two weeks later, which the former won. In December 2017, Ambrose suffered a triceps injury, reportedly rendering him out of action for nine months.
On the August 13, 2018 episode of Raw, Ambrose returned to assist Rollins against an attack from Drew McIntyre and Dolph Ziggler. Six days later, he assisted Rollins in winning the Intercontinental Championship at SummerSlam. The following night on Raw, Ambrose and Rollins aided Universal Champion Roman Reigns in attacking Braun Strowman when the latter attempted to cash-in his Money in the Bank contract, once again reuniting The Shield. At Hell in a Cell, Ambrose and Rollins were unsuccessful in defeating Ziggler and McIntyre for the Raw Tag Team Championship. In October, The Shield defeated Ziggler, McIntyre, and Strowman at Super Show-Down. Two nights later on Raw, they were defeated by the same trio in a rematch. After the match, a frustrated Ambrose walked away from his teammates.
On the October 22 episode of Raw, after Reigns announced his real-life leukemia and relinquished the Universal Championship, Ambrose and Rollins defeated Ziggler and McIntyre to capture the Raw Tag Team Championship for the second time. However, Ambrose immediately attacked Rollins after the match, turning heel for the first time since 2014. Two weeks later on Raw, Ambrose attacked Rollins again, after the latter lost the tag titles in a handicap match against AOP (Akam and Rezar). The following week, Ambrose burned his Shield vest and explained that being part of the group had made him weak. He would continue to taunt Rollins over the following weeks by stalking him, getting vaccinated against what he perceived to be Rollins's "illness", and ordering his own personal SWAT team to attack Rollins, subsequently proclaiming himself as "The Moral Compass of WWE". Ambrose defeated Rollins at TLC in December to win the Intercontinental Championship, beginning his third reign with title. Throughout the following weeks, he successfully defended his title against Tyler Breeze, Apollo Crews, and Rollins, before losing the championship to Bobby Lashley on the January 14, 2019 episode of Raw, in a triple threat match also involving Rollins, ending his reign at 29 days.
Ambrose entered the 2019 Royal Rumble match at number 14, but was eliminated by Aleister Black. The following night on Raw, he interrupted Royal Rumble winner Rollins and Triple H, proclaiming that Rollins never defeated him clean without interference and provoking Triple H into booking them in a match, which Ambrose subsequently lost. A few hours after Raw went off the air, it was reported that Ambrose had informed WWE officials that he would not be renewing his contract and would be leaving the company shortly after WrestleMania 35. WWE subsequently confirmed his decision in a statement.
After weeks of teasing a reunion, Ambrose reunited with Rollins and the recently returned Reigns on the March 4 episode of Raw, after they assisted Ambrose from an attack by Baron Corbin, Bobby Lashley, Drew McIntyre, and Elias the previous week, reverting Ambrose to a face once again. At Fastlane on March 10, The Shield defeated the team of McIntyre, Lashley, and Corbin. In his final singles matches in WWE, Ambrose would subsequently lose to McIntyre several times on Raw.
On the April 8 episode of Raw, Ambrose was scheduled to face Bobby Lashley in what was billed as Ambrose's last match on Raw. However, the match never took place as Lashley insulted Ambrose's wife, Renee Young, resulting in a brawl that ended with Ambrose being slammed through the announce table. After Raw went off the air, Ambrose joined Rollins and Reigns to address the fans, thank them for their support, and comment on his past accomplishments before celebrating with his Shield teammates. The following week on Raw, he made another appearance after the show went off the air. His final contractual match occurred at a special event called The Shield's Final Chapter on April 21, where he, Reigns, and Rollins defeated the team of Corbin, Lashley, and McIntyre. His contract expired on April 30.