Anoaʻi played football for three years at Pensacola Catholic High School and one year at Escambia High School. In his senior year, he was named Defensive Player of the Year by the Pensacola News Journal. He then attended Georgia Institute of Technology, where he was a member of the Georgia Tech Yellow Jackets football team along with Calvin Johnson, who later became a wide receiver in the National Football League (NFL). Anoaʻi was a three-year starter beginning in his sophomore year and was also one of the team captains as a senior. Anoaʻi was named to the first-team All-Atlantic Coast Conference (ACC) in 2006 and earned All-ACC first-team honors with 40 tackles, two recovered fumbles and 4.5 sacks.

After going undrafted in the 2007 NFL draft, Anoaʻi was signed by the Minnesota Vikings in May 2007. He was diagnosed with leukemia after his team physical and was released later that month. The Jacksonville Jaguars signed him in August 2007, only to release Anoaʻi less than a week later before the start of the 2007 NFL season.

A triple threat match between Reigns, Strowman and Lesnar for the Universal Championship was scheduled for the Crown Jewel event, however, on October 22, Reigns relinquished the title and announced his hiatus on Raw, revealing that his leukemia had returned after 11 years of privately battling it and being in remission. Following this announcement, Reigns would go on an indefinite hiatus to receive treatment. Reigns was first diagnosed in May 2007 when he was signed to the Minnesota Vikings, and went into remission around two years after the initial diagnosis.

In 2008, Anoaʻi was signed by the Edmonton Eskimos of the Canadian Football League (CFL). Wearing the number 99, Anoaʻi played for one season with the Eskimos, featuring in five games, of which he started three. Anoaʻi’s most notable game came against the Hamilton Tiger-Cats in September, where he tied for the team lead with five tackles and had a forced fumble. Anoaʻi was released by the Eskimos on November 10, and proceeded to retire from professional football.

Anoaʻi signed a contract with World Wrestling Entertainment (WWE) in 2010 and was later assigned to their developmental territory Florida Championship Wrestling (FCW). He made his televised debut on August 19, 2010, using the ring name Roman Leakee, in a 15-man battle royal, which was won by Alex Riley. On the January 16, 2011 episode of FCW, Leakee was a competitor in a 30-man Grand Royal, but was eliminated. Later in 2011, Leakee formed a tag team with Donny Marlow and the pair unsuccessfully challenged Calvin Raines and Big E Langston for the FCW Florida Tag Team Championship on July 8.

In January 2012, Leakee pinned FCW Florida Heavyweight Champion Leo Kruger in a non-title match. On the February 5 episode of FCW, he defeated Dean Ambrose and Seth Rollins in a triple threat match to become the number one contender to the FCW Florida Heavyweight Championship. He failed to win the championship when he lost to Kruger the following week. Leakee later won the FCW Florida Tag Team Championship with Mike Dalton and would drop the titles to CJ Parker and Jason Jordan shortly after.

After WWE rebranded FCW to NXT in August 2012, Anoaʻi, with the new ring name of Roman Reigns and a villain character, made his debut on the October 31 episode of NXT by defeating CJ Parker.

Roman Reigns made his main roster television debut as on November 18, 2012 at the Survivor Series pay-per-view event alongside Dean Ambrose and Seth Rollins, assaulting Ryback during the triple threat main event for the WWE Championship, allowing CM Punk to retain the title, thus establishing themselves as villains. The trio declared themselves The Shield and vowed to rally against “injustice”, while also denying working for Punk, even though they would routinely emerge from the crowd to attack Punk’s adversaries, including Ryback and WWE Tag Team Champions Team Hell No (Daniel Bryan and Kane). This led to a six-man tag team Tables, Ladders, and Chairs match at TLC: Tables, Ladders & Chairs on December 16, in which Reigns, Ambrose and Rollins defeated Team Hell No and Ryback in their debut match. The Shield continued to aid Punk in January 2013, attacking both Ryback and The Rock. On the January 28 episode of Raw, it was revealed that Punk and his manager Paul Heyman had been paying The Shield and Brad Maddox to work for them.

In August, The Shield began working for chief operating officer Triple H and The Authority. Their association with The Authority led them to begin a rivalry with Cody Rhodes and Goldust. At Battleground on October 6, Reigns and Rollins were defeated by Rhodes and Goldust in a non-title match. Reigns and Rollins would later lose the tag team titles to Rhodes and Goldust in a no disqualification match on the October 14 episode of Raw, following interference from Big Show. At Hell in a Cell on October 27, Reigns and Rollins failed to regain the championship in a triple threat tag team match. At Survivor Series, 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; Reigns would win the match for his team. At TLC: Tables, Ladders & Chairs on December 15, The Shield were defeated by CM Punk in a 3-on-1 handicap match, after Reigns accidentally speared Ambrose. At the Royal Rumble on January 26, 2014, Reigns entered the Royal Rumble match at number 15 and went on to eliminate 12 competitors in the match, a record that was later broken by Braun Strowman in 2018. Reigns would be the runner-up in the match after being lastly eliminated by Batista. The next night on Raw, The Shield competed in a six-man tag team match against Daniel Bryan, Sheamus and John Cena, with all three members of the winning team qualifying for the Elimination Chamber match for the WWE World Heavyweight Championship, which The Shield lost via disqualification after The Wyatt Family interfered and attacked Cena, Bryan and Sheamus. A six-man tag team match pitting The Shield against The Wyatt Family on February 24 at the Elimination Chamber pay-per-view was arranged, in which The Shield lost after Ambrose abandoned the match mid-way through.

Anoaʻi married Galina Joelle Becker in early December 2014. He has a daughter named Joelle, with whom he appeared in a public service announcement in June 2014. His wife gave birth to twin boys in 2016, followed by another set of twins in 2020.

On December 30, 2015 at a WWE house show, Anoaʻi had his nose broken during his match against Sheamus. He underwent nasal reconstruction surgery two months after the injury, which altered the appearance of his nose.

The next night on Raw, Vince McMahon granted Reigns a title rematch against Sheamus, under the stipulation that if Reigns lost, he would be forced to retire. Reigns managed to win after overcoming interferences from McMahon, Del Rio and Rusev, regaining the WWE World Heavyweight Championship in the process. McMahon then forced Reigns to defend his title in the 2016 Royal Rumble match on January 24. In the match, Reigns was eliminated by Triple H, who eventually went on to win the match, thus losing the championship. At Fastlane on February 22, Reigns defeated Brock Lesnar and Dean Ambrose in a triple threat match to receive a WWE World Heavyweight Championship match against Triple H at WrestleMania 32 on April 3, where he defeated Triple H in the main event to become the WWE World Heavyweight Champion for a third time. After WrestleMania, Reigns began a feud with AJ Styles and successfully defended the championship against him at Payback on May 1 and then again at Extreme Rules in an Extreme Rules match later that month. After the latter match, Reigns was attacked by a returning Seth Rollins.

Anoaʻi is of half-Samoan and half-Italian descent. Both his father Sika Anoaʻi, and his brother Rosey, who died on April 17, 2017, were professional wrestlers. As a member of the Anoaʻi family, he is a cousin to former professional wrestlers Yokozuna, Rikishi, Umaga, who died on December 4, 2009, The Tonga Kid and first cousin once-removed to The Usos and The Rock (non-biological).

Reigns returned on the November 13 episode of Raw and challenged The New Day (Big E, Kofi Kingston and Xavier Woods) to a six-man tag team match at Survivor Series. At the event on November 19, The Shield emerged victorious over The New Day. The following night on Raw, Reigns defeated The Miz for the Intercontinental Championship, thus becoming the twenty-eighth Triple Crown and seventeenth Grand Slam champion, the second member of The Shield after Ambrose to achieve the Grand Slam. Following his title win, Reigns would successfully defend the title against Elias, Jason Jordan, Cesaro and Samoa Joe before losing it back to The Miz on the 25th Anniversary of Raw on January 22, 2018, ending his reign at 63 days.

Reigns competed in the 2018 Royal Rumble match on January 28, but was the last participant eliminated by eventual winner Shinsuke Nakamura. After defeating Bray Wyatt on the February 5 episode of Raw, Reigns qualified for the Elimination Chamber match, which he won, earning the right to face Brock Lesnar for the Universal Championship at WrestleMania 34. At WrestleMania, Reigns failed to win the championship from Lesnar. They had a rematch for the championship at the Greatest Royal Rumble, this time in a steel cage match, which Reigns narrowly lost after spearing Lesnar through the cage wall.

On February 25, 2019, Reigns made his return to Raw, revealing that his leukemia is once again in remission to a huge ovation from the crowd. Later in the night, Reigns and Rollins would appear to assist Ambrose from an attack by Drew McIntyre, Bobby Lashley, Elias and Baron Corbin. The following week on Raw, Ambrose assisted Reigns and Rollins from another attack by the four, before the trio performed their signature pose, officially reuniting the group for the third time. The Shield defeated the team of McIntyre, Lashley and Corbin at Fastlane. On the March 25 episode of Raw, Reigns accepted a challenge from McIntyre for a match at WrestleMania 35. At the event, Reigns was successful in defeating McIntyre.

During the 2019 WWE Superstar Shake-up, Reigns was drafted to the SmackDown brand on the April 16 episode of SmackDown, with WWE’s announcers describing Reigns as “SmackDown’s greatest ever acquisition”, as well as the future of SmackDown and WWE. During the episode, Reigns attacked Elias and Vince McMahon. The following week, Elias challenged Reigns to a match at Money in the Bank which Reigns accepted and also won. On the May 20 episode of Raw, Reigns, who appeared via the wild card rule, was interrupted by Shane McMahon, who was still bothered by Reigns’ earlier attack on his father. Reigns then challenged Shane to a match at Super ShowDown, which the latter accepted. At Super ShowDown in June, Reigns lost to McMahon after interference from McIntyre. Three weeks later, Reigns defeated McIntyre at Stomping Grounds, despite interference from McMahon. The following night on Raw, Reigns was saved by The Undertaker from an assault from McMahon and McIntyre. Reigns and Undertaker teamed up to defeat McMahon and McIntyre in a No Holds Barred tag team match at Extreme Rules on July 14.

On December 31, 2019, Reigns appeared on the 2020 edition of Fox’s New Year’s Eve with Steve Harvey, where he defeated Dolph Ziggler in a pre-taped match.

In November, Reigns began a feud with King Corbin and his allies Dolph Ziggler and Robert Roode. Reigns was named team captain for SmackDown at Survivor Series, where he and his four teammates defeated Team Raw and Team NXT in a five-on-five-on-five tag team elimination match. During the match, Corbin caused Mustafa Ali to be eliminated. Reigns responded by spearing Corbin and allowing him to be eliminated. This led to a tables, ladders, and chairs match being arranged for the TLC pay-per-view, which Reigns lost after interference from Ziggler and The Revival (Dash Wilder and Scott Dawson). At the Royal Rumble on January 26, 2020, Reigns defeated Corbin in a falls count anywhere match, after receiving assistance from The Usos. Later that night, he entered the Royal Rumble match, but was the last competitor eliminated by the eventual winner Drew McIntyre. The following month at Super ShowDown, Reigns defeated Corbin in a steel cage match to end their feud.