Henry joined the Nation of Domination with Farooq, The Rock, Kama Mustafa and D'Lo Brown on January 12, 1998. After The Rock usurped Farooq's position as leader, Henry switched loyalties to The Rock. He also competed at WrestleMania XIV in a tag team battle royal, with Brown as his partner, but they did not win. After the Nation disbanded, he engaged in a short feud with The Rock, defeating him at Judgment Day: In Your House with help from Brown, and then forming a permanent team with Brown, gaining Ivory as a manager. During the next year, Henry gave himself the nickname "Sexual Chocolate", and was involved in controversial angles with Chyna. During a match at the August 1999 pay-per-view, SummerSlam, between Brown and Jeff Jarrett for the WWF Intercontinental and WWF European Championships (both held at the time by Brown), Henry turned on Brown and helped Jarrett win the match and the titles. The next night, Henry was awarded the European title by Jarrett in return for his help. Henry dropped the title one month later to Brown at the Unforgiven pay-per-view.
After this, Henry turned into a fan favorite, and was seen on television romancing WWF women from Chyna to Mae Young as part of the "Sexual Chocolate" character. He feuded with Viscera during this time as part of a storyline where Viscera splashed Mae Young while she was carrying Henry's child. Young would go on to give birth to a hand. Along with this, Henry was made part of various other embarrassing and infamous storylines.
Henry returned to the WWE in 2002 and was sent to the SmackDown! brand, where he developed an in-ring persona of performing "tests of strength" while other wrestlers took bets on the tests, but the gimmick met with little success. During this time he competed against such superstars as Chris Jericho and Christian. After being used sporadically on WWE (formerly WWF) television during 2002, as he was training for a weightlifting contest, and suffering a knee injury, he disappeared from television.
In August 2003, Henry returned to WWE television on the Raw roster, where he found some success as a member of "Thuggin' And Buggin' Enterprises," a group of African Americans led by Theodore Long who worked a race angle in which they felt they were victims of racism and were being held down by the "white man". During that time, Henry was involved in a brief program with World Heavyweight Champion Goldberg when former champion, Triple H, put a bounty on Goldberg. This was followed by a brief rivalry with Shawn Michaels, before he engaged in a rivalry with Booker T. After defeating Booker T twice, once in a street fight and once in a six-man tag team match, he lost to Booker T at the Armageddon pay-per-view in December 2003. He then tore his quadriceps and took the next year off to recover.
During the December 30, 2005 episode of SmackDown!, Henry made his return to television, as he interfered in a WWE Tag Team Championship match, joining with MNM (Joey Mercury, Johnny Nitro, and Melina), to help them defeat Rey Mysterio and Batista for the championship. A week later on SmackDown!, Henry got in a confrontation with the World Heavyweight Champion, Batista, and went on to interfere in a steel cage match between MNM and the team of Mysterio and Batista, helping MNM to retain their titles. Henry then had another match with Batista at a live event where Batista received a severely torn triceps that required surgery, forcing him to vacate his title. On the January 10, 2006 episode of SmackDown!, Henry was involved in a battle royal for the vacant World Heavyweight Championship. He was finally tossed out by Kurt Angle, who won the title.
A week later, Henry received assistance from Daivari, who turned on Angle and announced that he was the manager of Henry. With Daivari at his side, Henry would face Kurt Angle for the World Heavyweight title at the 2006 Royal Rumble in January, which he lost when Angle hit him with a chair (without the referee seeing) and pinned Henry with a roll-up.
On the March 10 episode of SmackDown!, after putting Kurt Angle through a table with a diving splash, Henry was then challenged to a casket match by The Undertaker at WrestleMania 22. Henry vowed to defeat The Undertaker and end his streak at WrestleMania, but was unsuccessful in this quest as The Undertaker would defeat Henry at the event. Henry would get a rematch against the Undertaker on the April 7 episode of SmackDown!, however it ended in a no contest when Daivari announced his new client, The Great Khali, who was also making his debut. Khali then went to the ring and started to attack the Undertaker, thus ending the feud between them.
During the rest of April and May, Henry gained a pinfall victory over the World Heavyweight Champion, Rey Mysterio in a non-title match. Henry would also enter the King of the Ring tournament, in which he was defeated by Bobby Lashley in the first round. He later cost Kurt Angle his World Heavyweight Championship opportunity against Mysterio, when he jumped off the top rope and crushed Angle through a table. Henry was then challenged by Angle to face off at Judgment Day, Henry then sent a "message" to Angle by defeating Paul Burchill. At Judgment Day, Henry defeated Angle by countout. Although winning, Angle got his revenge after the match by hitting Henry with a chair and putting him through a table.
Henry later went on what was referred to as a "path of destruction", causing injuries to numerous superstars. Henry "took out" Chris Benoit and Paul Burchill on this path of destruction, and attacked Rey Mysterio and Chavo Guerrero. These events led up to a feud with the returning Batista, whom Henry had put out of action with a legitimate injury several months beforehand. When Batista returned he and Henry were scheduled to face one another at The Great American Bash in July. Weeks before that event, however, on the July 15, 2006 episode of Saturday Night's Main Event, Henry was involved in a six-man tag team match with King Booker and Finlay against Batista, Rey Mysterio, and Bobby Lashley. During the match, Henry was injured, canceling the scheduled match at The Great American Bash, as Henry needed surgery. Doctors later found that Henry completely tore his patella tendon off the bone and split his patella completely in two.
Henry returned on the May 11, 2007 episode of SmackDown!, after weeks of vignettes hyping his return. He attacked The Undertaker after a World Heavyweight Championship steel cage match with Batista, allowing Edge to take advantage of the situation and use his Money in the Bank contract. Henry then began a short feud with Kane, defeating him in a Lumberjack Match at One Night Stand. Shortly after, Henry made an open challenge to the SmackDown! locker room, which nobody ever accepted. In the coming weeks he faced various jobbers—wrestlers who consistently lose to make their opponents look stronger—and quickly defeated them all. On August 3, he claimed that nobody accepted the open challenge to step into the ring with him because of what he had done to The Undertaker, presenting footage of his assault on the Undertaker. The Undertaker responded over the following weeks, playing various mind games with Henry. Henry finally faced The Undertaker again at Unforgiven in September, losing to him after being given a Last Ride Following an unscripted backstage interview, Henry burst into tears and fled from the arena.. Two weeks later, Henry lost a rematch to The Undertaker after The Undertaker performed a chokeslam on Henry.
After a short hiatus, Henry returned to WWE programming on the October 23 episode of ECW, attacking Kane, along with The Great Khali and Big Daddy V. Henry then began teaming with Big Daddy V against Kane and CM Punk, and was briefly managed by Big Daddy V's manager, Matt Striker. At Armageddon, Henry and Big Daddy V defeated Kane and Punk. Before WrestleMania XXIV aired, Henry participated in a 24-man battle royal to determine the number one contender for the ECW Championship, but failed to win.
As part of the 2008 WWE Supplemental Draft, Henry was drafted to the ECW brand. At Night of Champions, Henry defeated Kane and Big Show in a Triple Threat match to capture the ECW Championship in his debut match as an ECW superstar. Upon winning the title, it was made exclusive to the ECW brand once again. Henry's title win came nearly a full decade after he was awarded the European Championship, which was back in 1999 and the only title he held in WWE. A few weeks later, Hall of Famer Tony Atlas returned to WWE to act as Henry's manager. A month after Henry's title win, ECW General Manager, Theodore Long, unveiled a new, entirely platinum ECW Championship belt design. Henry would lose the title at Unforgiven in the Championship Scramble match to Matt Hardy.
Henry attempted to regain the championship throughout the end of 2008, including a match against Hardy at No Mercy, but was unsuccessful. Henry and Atlas then engaged in a scripted rivalry against Finlay and Hornswoggle, which included Henry losing a Belfast Brawl at Armageddon. At the start of 2009, Henry qualified for the Money in the Bank ladder match at WrestleMania XXV, and was involved in a series of matches with the other competitors on Raw, SmackDown, and ECW. He was unsuccessful at WrestleMania, however, as CM Punk won the match. In May, Henry began a rivalry with Evan Bourne, which began after Bourne defeated Henry by countout on the May 26 episode of ECW.
On June 29, Henry was traded to the Raw brand and redebuted for the brand that night as the third opponent in a three-on-one gauntlet match against Randy Orton, which he won, turning Henry into a face in the process. In August 2009, Henry formed a tag team with Montel Vontavious Porter and the two challenged the Unified WWE Tag Team Champions Jeri-Show (Chris Jericho and The Big Show) for the title at Breaking Point, but were unsuccessful. They stopped teaming afterwards, becoming involved in separate storylines, until the February 15, 2010 episode of Raw in which they defeated the Unified WWE Tag Team Champions The Big Show and The Miz in a non-title match. The next week they challenged The Big Show and The Miz in a title match but were unsuccessful. At Extreme Rules, Henry and MVP fought for a chance to become number one contenders to the Unified WWE Tag Team Championships, but were the second team eliminated in a gauntlet match by The Big Show and The Miz. The match would be won by The Hart Dynasty (Tyson Kidd and David Hart Smith). On May 10 episode of Raw Mark Henry was attacked by Batista.
It was later announced that Henry would mentor Lucky Cannon in the second season of WWE NXT. Cannon was eliminated on the August 10 episode of NXT. In September, Henry began teaming with Evan Bourne, starting at the Night of Champions pay-per-view, where they entered a Tag Team Turmoil for the WWE Tag Team Championship. They made it to the final two before being defeated by Cody Rhodes and Drew McIntyre. The team came to an end in October when Bourne suffered an injury and was taken out of action. Henry then formed a team with Yoshi Tatsu on the November 29 episode of Raw, defeating WWE Tag Team Champions Justin Gabriel and Heath Slater, after a distraction by John Cena. They received a shot at the championship the next week, in a fatal four-way elimination tag team match, which also included The Usos and Santino Marella and Vladimir Kozlov. Henry and Tatsu were the first team eliminated in the match.
In 2011, on the April 25 episode of Raw, Henry was drafted back to the SmackDown brand as part of the 2011 WWE Draft. In the main event of the night, Henry sparked a heel turn for his character when he attacked his teammates, John Cena and Christian. On the May 27 episode of SmackDown, Henry participated in a Triple Threat match against Sheamus and Christian to decide the number one contender to the World Heavyweight Championship, which was won by Sheamus. On the June 17 episode of SmackDown, Henry was scheduled to face an angry and emotionally unstable Big Show, who warned Henry not to get into the ring; Henry ignored the warning and Big Show assaulted Henry before the match could begin. This act would ignite a feud between the two; Henry would attack Big Show both backstage and during matches while on the July 1 episode of SmackDown, Big Show's music played during Henry's match against Randy Orton, causing Henry to be counted out and costing Henry a future shot at the World Heavyweight Championship. Henry reacted by destroying the audio equipment and manhandling a technician. Henry faced Big Show in a singles match at Money in the Bank and won. After the match, Henry crushed Show's leg with a chair, (kayfabe) injuring him, an act Henry would later reference as an induction into the "Hall of Pain". Henry would do the same to Kane on the following episode of SmackDown.
On the July 29 episode of SmackDown, Theodore Long informed Henry that he could no longer compete as no one dared to fight him. Sheamus interrupted, saying that he wasn't afraid of Henry before slapping him. On the August 5 episode of SmackDown, Henry defeated Vladimir Kozlov and crushed Kozlov's leg after the match. At SummerSlam, Henry defeated Sheamus by count-out after Henry slammed Sheamus through a ring barricade. On the August 19 episode of SmackDown, Henry won a 20-man Battle Royal to become the number one contender to the World Heavyweight Championship to face Randy Orton at Night of Champions and throughout weeks on SmackDown and Raw, Henry would attack Orton, getting an advantage over him. At Night of Champions, Henry defeated Orton to become World Heavyweight Champion for the first time in his 15 years with WWE. On the September 30 episode of SmackDown, Henry defeated The Great Khali in a non-title match and later crushed Khali's foot after the match. Henry successfully defended the title against Orton at Hell in a Cell in a Hell in a Cell match.
On the October 7 episode of Smackdown, Big Show returned and choke-slammed Henry through the announce table, thus earning a title shot against Mark Henry at Vengeance. During the match, Henry superplexed Big Show from the top rope, causing the ring to collapse from the impact, and the match ruled a no contest. Henry also began a feud with the Money in the Bank briefcase holder Daniel Bryan on the November 4 episode of SmackDown, challenging Bryan to a non-title match to prove that Bryan could not become champion. During the match, Big Show knocked out Henry, making him win by disqualification. Show then urged Bryan to cash in his contract, but Henry recovered and attacked both Bryan and Big Show before the match could start. At Survivor Series. Henry retained the World Heavyweight Championship against Big Show after a low blow that disqualified Henry. Angered by Henry's cowardice, Big Show crushed Henry's ankle with a steel chair. On November 25, Henry was knocked out again by Big Show, at which point Bryan cashed in his briefcase for a title match and quickly pinned Henry. However, SmackDown authority figure Theodore Long revealed that Henry was not medically cleared to compete and voided the match, so Henry remained champion and the briefcase was returned to Bryan. Later that night, Bryan won a Fatal-Four Way match to face Henry for the World Heavyweight Championship in a steel cage. On the November 29 of SmackDown, Henry defeated Bryan to retain his championship.
At TLC: Tables, Ladders & Chairs, Henry lost the World Heavyweight Championship to Big Show in a chairs match. After the match, Henry knocked Big Show out, resulting in Daniel Bryan cashing in his Money in the Bank to win his first World Heavyweight Championship. On the January 20 episode of SmackDown, Bryan retained the championship against Henry in a Lumberjack match after Bryan provoked the lumberjacks to come in and attack them to cause a no contest. At the 2012 Royal Rumble event, Henry faced Bryan and Show in a triple threat steel cage match for the world title, but Bryan escaped the steel cage to retain his title.
On the February 3, 2012 episode of SmackDown, Henry was suspended indefinitely in story-line by SmackDown General Manager Theodore Long after Henry physically accosted Long as he demanded a one-on-one rematch that night with Bryan. In reality, Henry suffered a hyper-extended knee the previous week. Henry returned to in-ring action on the February 20 episode of Raw, losing to Sheamus. On the April 2 and 9 episodes of Raw, Henry faced CM Punk for the WWE Championship which he won by count-out and disqualification; but as a result Punk retained his title. On the April 16 episode of Raw, Punk defeated Henry in a no-disqualification, no count-out match to retain the WWE Championship. On May 14, Henry announced he was going under a career-threatening surgery for an injury. After a nine-month absence, Henry made his return on the February 4, 2013 episode of Raw, brutally attacking Daniel Bryan, Rey Mysterio and Sin Cara. Four days later on SmackDown, Henry defeated Randy Orton to earn a spot in the number one contenders' Elimination Chamber match for the World Heavyweight Championship at Elimination Chamber. At the pay-per-view on February 17, Henry eliminated Daniel Bryan and Kane before being eliminated by Randy Orton. After his elimination, Henry attacked the three remaining participants before being escorted out by WWE officials. He then would win several squash matches, until he moved into a feud with Ryback. After a match on the March 15, 2013 episode of SmackDown, it was announced that they would have a match at WrestleMania 29. On April 7 at Wrestlemania 29, Henry defeated Ryback in a singles match. Later that month, Henry reignited a feud with Sheamus, after the two repeatedly attacked each other backstage. On the April 19 episode of SmackDown, Henry teamed up with old rival Big Show to defeat Sheamus and Randy Orton in a tag team match. With Orton and Show out of the picture, Henry would continue to feud with Sheamus as the two started testing each other's strength, during which, Henry shattered the Guinness World Record when he pulled two tractor trailers weighting over 110,000 pounds 20 feet across a parking lot. Their rivalry built to a strap match on May 19 at Extreme Rules, where Sheamus emerged victorious.
Henry returned on the June 17 episode of RAW, interrupting John Cena and faking a retirement, which he then used to attack Cena with a Worlds Strongest Slam. Later that night, Henry was granted a WWE Championship match against John Cena at the pay-per-view, Money in the Bank, on July 14. On July 14 at the pay-per-view, Henry failed in his title challenge against Cena after submitting to the STF. The following night on the July 15 Raw, Henry delivered a promo congratulating Cena on his win, but was attacked by The Shield, indicating a face turn for Henry. He would continue his face turn next week by confronting The Shield, and teaming together with The Usos to fend them off. On the August 12 episode of Raw, Henry competed in a twenty-man number one contender battle royal for the United States Championship, but was the last man eliminated by Rob Van Dam. After the match, Henry and Van Dam were confronted by The Shield, before the returning Big Show came to their aid. Four days later on SmackDown, Henry, Show, and Van Dam defeated the Shield in a six-man tag team match. Henry then took some time off after this. He returned in November at Survivor Series to accept Ryback's challenge by defeating him, sporting a new look, with his head shaved. Henry tried to confront Brock Lesnar during separate encounters after Lesnar's return, resulting in Henry receiving an F5 the first time and then Lesnar injured Henry's arm after getting it in a Kimura lock hold, causing Henry to wail in pain and be absent. He returned on 10 February and answered Dean Ambrose's open challenge for the WWE United States Championship, but never won the title due to interference by The Shield cohorts. In March, Henry would suffer another attack from Lesnar, this time resulting in Henry receiving an F-5 through the announcing table. Henry soon recovered and had another match with Ambrose for the U.S. Title, but was again unsuccessful. On August 4 he defeated Damien Sandow after a few months absence. On the August 15 edition of Smackdown, Henry defeated Luke Harper by disqualification which led to a tag match with Henry and Big Show vs. The Wyatts where Henry pinned Erick Rowan.
At Night of Champions, Henry lost to Rusev via submission. On the following night on Raw, Henry lost to Rusev again by knockout via submission. On the October 27 episode of Raw, Henry turned heel when he attacked Big Show during a tag team match. On the November 3 Raw, he lost to Big Show via disqualification and slammed Big Show onto the steel steps. On the November 10 Raw, he joined The Authority's team to face John Cena's team at Survivor Series. On November 23 at Survivor Series, Henry was the first to be eliminated from Team Authority 50 seconds into the match after being knocked out by The Big Show. Ironically however, Big Show turned heel and aligned with The Authority during the match. Henry then took another hiatus due to an unspecified injury.
Henry returned on the March 12, 2015 episode of SmackDown, confronting Roman Reigns for having a lack of identity and for not being respected, ultimately resulting in Reigns attacking Henry. The attack caused Henry to become a "believer" in Reigns turning face again the process. At WrestleMania 31, Henry competed in the Andre the Giant Memorial Battle Royal, but was unsuccessful as he was eliminated by the Ascension. After a two-month hiatus, Henry once again returned as the surprise replacement for an injured Rusev in the Elimination Chamber Match for the vacant Intercontinental Championship at the Elimination Chamber pay-per-view. He, however, failed to win the match as he was eliminated by Sheamus. On the June 8 episode of Raw, Henry became a heel once again when he faced Reigns for his Money in the Bank spot, in which he was unsuccessful. After the match, Henry attacked Reigns. On the June 22 Raw, Henry was defeated by Ryback. On the July 13 episode of Raw, The Prime Time Players revealed their tag team partner to be Henry against the heel tag team The New Day, seemingly turning Henry face again. His face turn was confirmed when he once again teamed with The Prime Time Players to defeated The New Day on the August 6, 2015 episode of SmackDown. Henry spent the remainder of 2015 suffering back to back loses in singles matches, losing to the likes of, Big Show, Sheamus and Neville while constantly switching between face and heel. At Tribute to the Troops, Henry defeated Bo Dallas.
At the start of 2016 at Royal Rumble, Henry teamed with Jack Swagger to win a Fatal-4-Way Tag Team Match to earn their spots in the Royal Rumble Match. Despite this victory, Henry entered the Rumble Match at #22 and lasted only 47 seconds when he was quickly eliminated by The Wyatt Family. His partner Swagger only lasted 29 seconds. On February 8 Episode of Raw, Henry walked out on The New Day during an 8-Man Tag Team Tables Match against The Usos and The Dudley Boyz. On February 15 episode of Raw Henry lost to Big E of The New Day. At WrestleMania 32, Henry entered his third André the Giant Memorial Battle Royal, he eliminated Tyler Breeze and made it to the final six competitors until being eliminated by Kane and Darren Young.
On July 19, at the 2016 WWE Draft, Henry was drafted to Raw. On the August 1 episode of Raw, Henry claimed he still "had a lot left in him" when he spoke of reviving the Hall of Pain and his participation in the Olympics. Acting general manager Mick Foley gave Henry a United States Championship match, but Henry would lose by submission to Rusev.