Hardy worked as a jobber for the World Wrestling Federation (WWF) from 1994 up until he signed a full-time contract in 1998. His first WWF match was against Nikolai Volkoff on May 23, 1994, which he lost by submission. Hardy made his Monday Night Raw debut on July 11, 1994, losing to Crush. A night later at a taping of WWF Wrestling Challenge, he lost a match against Owen Hart. He continued to wrestle sporadically in the WWF throughout 1994 and 1995, losing matches against Crush, Razor Ramon, Hakushi, Owen Hart, the imposter Undertaker, Hunter Hearst Helmsley and "The Ringmaster" Steve Austin.
Hardy teamed with his brother Jeff for the first time in the WWF in 1996, losing to teams such as The Smoking Gunns and The Grimm Twins on WWF television. Matt and Jeff had a short lived feud with The Headbangers (Thrasher and Mosh), losing to the duo twice in 1997. It was during this time that Matt and Jeff experimented with different ring names, at one stage being called Ingus (Matt) and Wildo Jinx (Jeff). In Matt's final singles match for the promotion before signing a full-time contract he lost to Val Venis on a taping of Shotgun in 1998.
It was not until 1998, however, (at the height of The Attitude Era) that the Hardy brothers were given full-time WWF contracts. The Hardy Boyz used a cruiserweight, fast-paced high flying style in their matches, often leaping from great heights to do damage to their opponents (and themselves in the process). In 1999, while feuding with Edge and Christian, the duo briefly picked up Michael Hayes as a manager.
At King of the Ring, The Hardyz defeated Edge and Christian to earn the #1 contendership for the WWF Tag Team Championship. On July 5, they defeated The APA to win their first Tag Team Championship. They soon dumped Hayes and briefly picked up Gangrel as a manager, after Gangrel turned on Edge and Christian. At No Mercy, The Hardyz defeated Edge and Christian in the first ever tag team ladder match. At the Royal Rumble pay-per-view, The Hardyz defeated The Dudley Boyz in the first ever tag team tables match. They competed against The Dudley Boyz and Edge and Christian for the Tag Team Championships at WrestleMania 2000 in the first ever Triangle Ladder match, but were unsuccessful.
Hardy won the Hardcore Championship on April 24, 2000, on Raw Is War, by defeating Crash Holly, but lost it back to Holly three days later on SmackDown!, when Holly applied the "24/7 rule" during Hardy's title defense against Jeff. The Hardy Boyz then found a new manager in Matt's real-life girlfriend Lita. Together, the three became known as "Team Xtreme".
The Hardy Boyz competed in the first ever Tables, Ladders, and Chairs match, for the WWF Tag Team Championship against The Dudley Boyz and Edge and Christian, but were unsuccessful. At Unforgiven, The Hardyz defeated Edge and Christian in a steel cage match to win the tag team championship, and successfully retained it the following night on Raw is War against Edge and Christian in a ladder match.
In April 2001, The Hardyz began feuding with Stone Cold Steve Austin and Triple H (known as The Power Trip), which also led to a singles push for both Matt and Jeff. Hardy helped Jeff defeat Triple H for the Intercontinental Championship, and shortly after Hardy defeated Eddie Guerrero to win the European Championship on SmackDown!. At Backlash, he retained the title against Guerrero and Christian in a triple threat, and against Edge the following night on Raw.
Throughout the year, the Hardy Boyz continued to win as a tag team, winning the WWF Tag Team Titles two more times, and the WCW Tag Team Championship during the Invasion. By the end of the year, the Hardy Boyz began a storyline where they were having trouble co-existing. This culminated in a match between the two, with Lita as the guest referee, at the Vengeance pay-per-view, which Jeff won. Hardy defeated Jeff and Lita the following night on Raw in a two-on-one handicap match.
At the beginning of 2002, it seemed Team Xtreme had patched things up. After the brand extension, however, Hardy was relegated to Heat while Jeff wrestled on the main show, Raw. On the August 12 episode of Raw, Hardy turned heel by attacking Jeff during Jeff's match against Rob Van Dam, because Hardy was frustrated at not receiving a match against Van Dam for the number one contendership for the Intercontinental Championship. A short time later, Hardy joined the SmackDown! roster, and began dubbing himself "Matt Hardy: Version 1", complete with a "version 1" hand signal. Hardy defeated The Undertaker on the September 12 and October 3 episodes of the show, due to interference from Brock Lesnar.
Along with his "Mattitude Follower" Shannon Moore in his corner, 2003 began with Hardy frantically trying to lose weight to get under the 215 lb (98 kg) weight limit to compete for the Cruiserweight Championship. After just barely making weight, Hardy defeated Billy Kidman at No Way Out to win the Cruiserweight title. At WrestleMania XIX, he successfully defended it against Rey Mysterio. Hardy lost the Cruiserweight Championship to Mysterio in the main event of the June 5 episode of SmackDown - the first and only time a Cruiserweight Championship match main evented a show.
After dropping the Cruiserweight Championship, Hardy briefly feuded with Eddie Guerrero, but was unsuccessful in capturing Guerrero's United States Championship or Tag Team Championship. The Mattitude faction then expanded to include Crash Holly as Moore's "Moore-on" (apprentice). He later disbanded the group in November and returned to Raw in order to be able to travel and work with his then girlfriend Lita, who just returned from an injury. On his first night back, he turned on Lita in storyline after teasing a proposal to her. He defeated Christian, who was vying for Lita's affections, on the following edition of Raw.
In April 2004, Hardy saved Lita from getting attacked by Kane, turning face in the process. Hardy defeated Kane at Vengeance, but lost a match against Kane at SummerSlam. On the August 23 episode of Raw, Hardy was chokeslammed off the stage by Kane. Hardy then spent almost a year off from wrestling due to a severe knee injury.
Along with his friend Rhyno, Hardy was released by WWE on April 11, 2005. Hardy's release was largely due to unprofessional conduct with social media after discovering that Lita was having a real-life affair with Edge. The public knowledge of the affair and Hardy's release led to Edge and Lita receiving jeers from the crowds at WWE events, often resulting in chants of "You screwed Matt!", and, "We want Matt!", which meant kayfabe storylines being affected considering that Lita was married to Kane at the time in kayfabe. Edge and Lita used the affair and fan backlash to become a hated on-screen couple, which led to Lita turning heel. On the June 20 episode of Raw, during the storyline wedding of Edge and Lita, Hardy's entrance music and video were played when the priest asked if anyone had a reason why Edge and Lita should not be wed.
On July 11, 2005 on Raw, Hardy attacked Edge backstage and again later during Edge's match with Kane. Before being escorted out of the building by security, Hardy stated that Edge and Lita would pay for their actions while security officials and event staff were trying to restrain him. Similar occurrences repeated during the following two weeks.
On the August 1 episode of Raw, Vince McMahon officially announced Hardy's return to WWE, adding that Hardy would face Edge at SummerSlam. Hardy made his in-ring return, defeating Snitsky on the August 8 Raw. Seconds after the victory, Hardy was attacked by Edge, and as he was being carried backstage, Matt counterattacked Edge in the locker room. On August 21 at SummerSlam, their match came to a premature end when Edge dropped Hardy onto the top of a ring post, causing him to bleed heavily. The referee ended the match on the grounds that Hardy could not continue, and Edge was declared the winner. After SummerSlam, the two continued fighting on Raw, including a Street Fight that resulted in Hardy performing a Side Effect on Edge off the entrance stage and into electrical equipment below. At Unforgiven, Edge faced Hardy in a steel cage match. Hardy caught an interfering Lita with the Twist of Fate and won the match with a leg-drop off the top of the cage. Hardy and Edge faced each other at WWE Raw Homecoming in a Loser Leaves Raw ladder match. Edge's briefcase holding his Money in the Bank Contract for his WWE Championship opportunity was suspended above the ring. The winner of the match received the contract and the loser was forced to leave Raw. Edge tied Hardy's arms in the ropes, and Lita trapped Hardy in a crucifix hold, leaving Hardy only able to watch Edge win.
With his defeat at the hands of Edge, Hardy was moved to the SmackDown! brand where he re-debuted with a win over Simon Dean on October 21 in Reno, Nevada. One week later, Hardy won the fan vote to represent Team SmackDown (alongside Rey Mysterio) to challenge Team Raw (Edge and Chris Masters) at Taboo Tuesday. Edge, however, refused to wrestle and sent Snitsky in place of him in the match, which Hardy and Mysterio won.
Back on SmackDown!, Hardy started an angle with MNM (Johnny Nitro and Joey Mercury) and their manager Melina when Melina approached Hardy, seemingly wanting Hardy to join with her team. Hardy refused the offer, which led to him facing the tag team on several occasions with a variety of partners. On July 25, after the SmackDown! taping, Hardy was taken out of action after doctors found the remnants of the staph infection that had plagued him the previous year. He was sidelined until August 25 while he healed.
Upon his return to action, Hardy feuded against reigning Cruiserweight Champion Gregory Helms. At No Mercy, in both of their hometown, Cameron, North Carolina, Hardy beat Helms. The two met again at Survivor Series, where Hardy's team won in a clean sweep.
On the November 21, 2006 episode of ECW on Sci Fi, Matt and Jeff competed in a match together for the first time in almost five years, defeating The Full Blooded Italians. At December to Dismember, the Hardy Boyz issued an open challenge to any tag team who wanted to face them. MNM answered their challenge by reuniting at December to Dismember, a match won by the Hardy Boyz. At Armageddon, Hardy and Jeff competed against Paul London and Brian Kendrick, MNM, and Dave Taylor and William Regal in a Ladder match for the WWE Tag Team Championship but lost. Subsequently, he and Jeff feuded with Joey Mercury and Johnny Nitro after the legitimate incident where they injured Mercury's face at Armageddon 2006. This led to a long term rivalry, and at the 2007 Royal Rumble, Hardy and Jeff defeated MNM. Mercury and Hardy continued to feud until Mercury was released from WWE in March.
The night after WrestleMania 23 on Raw, the Hardys competed in a 10-team battle royal for the World Tag Team Championship. They won the titles for the sixth time from then WWE Champion John Cena and Shawn Michaels after last eliminating Lance Cade and Trevor Murdoch. This started a feud with Cade and Murdoch, and the Hardys successfully retained their World Tag Team Championship in their first title defense at Backlash. The Hardy Boyz also successfully retained their titles at Judgment Day against Cade and Murdoch. One month later at One Night Stand, they defeated The World's Greatest Tag Team to retain the titles in a Ladder match. The following night on Raw, Vince McMahon demanded that The Hardys once again defend their championships against Cade and Murdoch. The Hardys were defeated after Murdoch pushed Jeff's foot off the bottom rope during Cade's pinfall, causing the three count to continue. They invoked their rematch clause against Cade and Murdoch at Vengeance: Night of Champions, but were unsuccessful.
On the July 6, 2007 episode of SmackDown!, Hardy won a non-title match against United States Champion Montel Vontavious Porter (MVP), which resulted in a feud between the two. Hardy was defeated by MVP at The Great American Bash for the United States Championship. MVP then claimed that he was "better than Hardy at everything", which led to a series of contests between Hardy and MVP, such as a basketball game, an arm wrestling contest, and a chess match which MVP "sneezed" on and ruined when Hardy put him in check. MVP challenged Hardy to a boxing match at Saturday Night's Main Event, however MVP was legitimately diagnosed with the heart condition Wolff-Parkinson-White syndrome. Since MVP was unable to compete, Hardy faced his replacement, former world champion boxer, Evander Holyfield. The match ended in a no contest after MVP entered the ring to verbally abuse Holyfield, who then knocked him out. MVP also challenged Hardy to a beer drinking contest at SummerSlam, but as revenge for what happened at SNME, Hardy allowed Stone Cold Steve Austin to replace him; Austin simply performed a stunner on MVP then kept drinking.
After a segment involving MVP inadvertently choosing Hardy as his tag-team partner, Theodore Long promptly set up a match against Deuce 'n Domino for the WWE Tag Team Championship which the duo were able to win, therefore setting up Hardy's first reign as WWE Tag Team Champion. Hardy and MVP retained the titles at Unforgiven in a rematch against former champions Deuce 'n Domino. Hardy was scheduled to face MVP at Cyber Sunday, but due to a real-life head injury sustained on the previous episode of SmackDown!, he was not medically cleared to compete. As part of the storyline, Hardy continually asked MVP for a shot at the United States Championship but MVP refused stating that he was more focused on the Tag Team Championship.
On the November 16 episode of SmackDown!, Hardy and MVP dropped the WWE Tag Team Championship to John Morrison and The Miz. Despite the fact that Hardy was hurt, MVP immediately invoked the rematch clause. After the rematch, in which Hardy was forced to tap out, MVP attacked Hardy, repeatedly targeting his knee. It was later confirmed by WWE.com that Hardy had suffered an injury at his former partner's hands and that he might not be able to compete at Survivor Series. Despite his absence at the pay-per-view, his team was able to win the match. On November 21, WWE's official website reported that Hardy underwent an emergency appendectomy in Tampa, Florida after his appendix burst. Hardy made an appearance at the December 31 episode of Raw supporting his brother Jeff. To further Jeff's storyline with Randy Orton, however, Hardy was attacked by Orton. Hardy made his return at a live event in Muncie, Indiana on March 1, 2008.
On March 30, 2008, at WrestleMania XXIV, during the Money in the Bank ladder match, Hardy cut through the crowd and attacked MVP to prevent him from winning the match. He made his official in-ring return the next night on Raw, losing a singles match to WWE Champion Randy Orton. On the April 4 episode of SmackDown!, Hardy faced MVP in a non-title match, which he won, re-igniting their storyline rivalry. On April 27, 2008, Hardy defeated MVP to win the United States Championship at Backlash, and successfully retained his title against MVP five days later on SmackDown.
Hardy declared himself as a fighting champion that would take on all challenges, defending the United States championship against Shelton Benjamin, Elijah Burke, Chuck Palumbo, Mr. Kennedy, Chavo Guerrero and Umaga. Hardy was drafted to the ECW brand on the June 23, 2008 episode of Raw during the 2008 WWE Draft, in the process making the United States Championship exclusive to ECW. He dropped the United States Championship to Shelton Benjamin at the Great American Bash pay-per-view on July 20, 2008, which meant that the title returned to SmackDown.
On the July 22 episode of ECW, Hardy became the number one contender to Mark Henry's ECW Championship after defeating John Morrison, The Miz and Finlay in a fatal four-way match. He won the title match at SummerSlam by disqualification due to interference from Henry's manager, Tony Atlas, thus he failed to win the title. Due to the ending of the pay-per-view match, Hardy received a rematch for the title on the next episode of ECW, but again failed to win the title when Henry pinned him after a distraction by Atlas. At Unforgiven, Hardy won the ECW Championship during the Championship scramble match, defeating then-champion Henry, The Miz, Finlay and Chavo Guerrero by pinning the Miz with three minutes left, marking his first world heavyweight championship win. He continued to feud with Henry until No Mercy, where Hardy successfully retained the title. Hardy lost the title to Jack Swagger on the January 13, 2009 episode of ECW, which was taped on January 12.
At the 2009 Royal Rumble pay-per-view, after losing an ECW Championship rematch to Swagger, Hardy turned on his brother when he hit Jeff with a steel chair, allowing Edge to win the WWE Championship, turning heel in the process. On the January 27, 2009 episode of ECW, it was announced by General Manager Theodore Long that Hardy had requested, and been granted, his release from ECW and had re-signed with the SmackDown brand. As part of the buildup to this feud, Matt strongly implied that he was responsible for all of Jeff's accidents leading back to November, including an assault in a hotel stairwell that prevented Jeff from appearing at Survivor Series, an automobile accident where Jeff's car was run off the road, and a pyrotechnics malfunction where part of the pyro from Jeff's entrance was fired directly at Jeff, in an attempt to stop Jeff holding the WWE Championship. Despite Hardy's attempts to goad Jeff into fighting him, Jeff refused to fight his brother, but, on the March 6 episode of SmackDown!, Jeff attacked him during a promo where Matt implied that he was also responsible for the fire that burned down Jeff's house, going so far as to reveal that he had in his possession a dog collar that supposedly belonged to Jeff's dog, Jack (who perished in the fire), that he claimed to have salvaged from the wreckage of the house. At WrestleMania XXV, Matt defeated Jeff in an Extreme Rules match, and in a stretcher match on the following episode of SmackDown.
On the April 13 episode of Raw, Hardy was drafted to the Raw brand as part of the WWE draft. Despite the fact that the two were on different brands, he continued his feud with Jeff. Two weeks later, in a rematch from WrestleMania, Hardy lost to Jeff in an "I Quit" match at Backlash, in which he legitimately broke his hand.
Hardy continued to wrestle with his hand in a cast, incorporating it into his persona and claiming that he was wrestling under protest. He reignited his feud with MVP on Raw for the United States Championship. He also formed a tag team with William Regal, and the two acted as henchmen for General Manager Vickie Guerrero. At the June 22 taping of WWE Superstars, Hardy suffered yet another injury, when his intestines went through his abdominal wall, during a triple threat match against MVP and Kofi Kingston. Hardy had suffered a tear in his abdominal muscle two years previously, but had not needed surgery until it worsened, and became a danger to his health.
He was then traded to the SmackDown brand on June 29, and underwent surgery for the torn abdominal muscle on July 2. He made his return on the August 7 episode of SmackDown as the special guest referee in the World Heavyweight Championship match between his brother, Jeff, and CM Punk, and helped Jeff retain the championship by counting the pinfall. The following week Hardy turned face again when saved his brother when CM Punk and The Hart Dynasty attacked both Jeff and John Morrison. On the August 21 episode of SmackDown, after apologizing for his past actions towards Jeff and admitting that he was not behind any of Jeff's accidents, he had his first match back after his injury when he teamed with Jeff and John Morrison to defeat The Hart Dynasty and CM Punk, when Matt pinned Punk.
In early 2010, Hardy began an on-screen relationship with Maria; but was brief and the relationship ended when Maria was released from her WWE contract. On the March 5 episode of SmackDown, Hardy qualified for the Money in the Bank ladder match at WrestleMania XXVI by defeating Drew McIntyre, but was unsuccessful at WrestleMania, as the match was won by Jack Swagger. Hardy was suspended by Vince McMahon because he attacked McIntyre after McIntyre lost to Kofi Kingston at Over the Limit. He was able to get his revenge on McIntyre during the Viewer's Choice episode of Raw when chosen as the opponent for McIntyre, with General Manager Theodore Long stating that Hardy was suspended from SmackDown, but not from Raw. On the following episode of SmackDown, however, Vickie Guerrero announced that, per orders of Vince McMahon, Hardy had been suspended from all WWE programming. However, at Fatal 4-Way, Hardy prevented McIntyre from regaining the Intercontinental Championship, thus continuing their feud. On the following edition of SmackDown, he was reinstated by Long and had a match with McIntyre, which Hardy won. After the match, it was announced that McIntyre's visa had legitimately expired and was sent back to Scotland, thus ending their feud.
On October 15, 2010, WWE announced that Hardy had been released from his contract.
At WrestleMania 33 on April 2, Matt made his surprise return to WWE, along with his brother Jeff, being added as last-minute participants in the ladder match for the Raw Tag Team Championship against the teams of Gallows and Anderson, Cesaro and Sheamus, and Enzo and Cass. Afterwards on Raw Talk, Matt mentioned that the Hardy Boyz had successfully completed the Expedition of Gold after winning the Raw Tag Team Championship. At Payback, the Hardy Boyz retained their championships against Cesaro and Sheamus, who attacked them after the match. The next night on Raw, Cesaro and Sheamus explained their actions, claiming the fans were more supportive of 'novelty acts' from the past like The Hardy Boyz, who they feel did not deserve to be in the match at WrestleMania 33. Subsequently, at Extreme Rules, the Hardy Boyz lost the titles in a steel cage match against Cesaro and Sheamus, and failed to regain it back the following month at the inaugural Great Balls of Fire event. Afterwards, it was revealed that Jeff had gotten injured and would be out for an estimated six months, thus Matt began wrestling in singles matches.
During his feud with Bray Wyatt, Hardy introduced his "Woken" gimmick. Wyatt defeated Hardy at Raw 25 on January 22, 2018, and Hardy defeated Wyatt at Elimination Chamber on February 25. Their final match happened on the March 19 episode of Raw, dubbed The Ultimate Deletion, with Hardy winning after distractions from Señor Benjamin. Wyatt then disappeared after being thrown into the Lake of Reincarnation. At WrestleMania 34 on April 7, Hardy competed in the annual André the Giant Memorial Battle Royal, and won the match due to a distraction by the returning Wyatt.
After WrestleMania, Hardy and Wyatt performed as a tag team, sometimes referred to as The Deleters of Worlds. They won a tournament for the vacant Raw Tag Team Championship, defeating Cesaro and Sheamus at Greatest Royal Rumble in Jeddah, Saudi Arabia. However, they lost the titles at Extreme Rules to the B-Team (Bo Dallas and Curtis Axel). On the July 23 episode of Raw, Hardy and Wyatt attacked the B-Team, after losing against them in their rematch clause for the titles. On the July 30 episode of Raw, Hardy and Wyatt were defeated by The Revival in an impromptu match. Following this, Hardy revealed that he was taking time off due to his back fusing with his pelvis, effectively disbanding the team.
After more than seven months of absence from television, Hardy returned to WWE, on the February 26, 2019 episode of SmackDown, teaming with his brother Jeff for the first time since August 2017, to defeat Cesaro and Sheamus. At WrestleMania 35 on April 7, Matt competed in the André the Giant Memorial Battle Royal alongside Jeff, but both were eliminated by eventual winner Braun Strowman. Two days later on SmackDown, The Hardy Boyz defeated The Usos to win the SmackDown Tag Team Championship. The reign only lasted 21 days (recognized as 20 days by WWE), as they had to vacate the title due to Jeff seriously injuring his knee; this was explained in storyline as injuries afflicted by Lars Sullivan.
After his brother's injury, Matt began to appear on WWE programming less frequently. At Super Showdown on June 7, Hardy competed in the 51-man Battle Royal, which was eventually won by Mansoor.
After a short hiatus, Hardy returned to the Raw brand on the November 25 episode, losing to Buddy Murphy.
On the February 10, 2020 episode of Raw, Hardy made an appearance where he confronted Randy Orton about Orton’s attack on Edge two weeks earlier. Hardy was then viciously attacked by Orton. The following week on Raw, an injured Hardy appeared and was once again assaulted by Orton. This would ultimately be Hardy's last appearance as his contract expired on March 2.