Practically all of the other sports whose athletes fill the ESPN 100 have long histories, much of which had to be set aside because this survey narrows its focus to just the 21st century's greatest performers. For mixed martial arts, though, the past 25 years encompass nearly the entirety of the sport's existence.
Sure, in assessing the best of the best, we did have to discard the dominance of Royce Gracie at UFC 1 in 1993 and in subsequent early events. But most of the greatest achievements in MMA have taken place since 2000. The sport has grown up in this century. No longer can the top competitors be specialists in just a single combat discipline that opponents have no experience with and are ill equipped to handle, as was the case in the formative days. Now, everyone in MMA is well rounded and dangerous everywhere. And they're from everywhere, too, as are the fans of this fully global sport.
The only MMA fighters who made the overall ESPN 100 were Jon Jones and Georges St-Pierre, the consensus picks for the sport's greatest of all time. But we have gone back to our MMA panel to fill out a full top 10 of the greatest fighters in men's MMA.
1. Jon Jones
Key accomplishments: UFC light heavyweight and heavyweight champion, youngest fighter to win a UFC championship, most wins in UFC light heavyweight history (20), most wins in UFC title fights (15), tied for most successful title defenses in UFC history (11), longest unbeaten streak in UFC history (19), UFC Hall of Famer
There's a reason UFC president Dana White calls Jones the greatest mixed martial artist to ever live. In a sport where the margin between victory and defeat is razor thin, Jones has managed to go 16 years without being defeated by an opponent (his only "loss" came via controversial DQ to Matt Hamill in 2009). After becoming the youngest fighter to win a UFC championship in 2011, Jones went scorched earth on a litany of Hall of Fame caliber fighters for the next four years with dominant wins over the likes of Daniel Cormier, Quinton "Rampage" Jackson, Lyoto Machida, Vitor Belfort and Rashad Evans. Not only did he beat them, but he did so by playing to his opponent's strengths and then running roughshod over them. The résumé is undeniable, and the accolades are still piling up. -- Andreas Hale
2. Georges St-Pierre
Key accomplishments: UFC Hall of Famer, UFC welterweight and middleweight champion, nine UFC welterweight title defenses
No fighter in UFC history bridged the gap better from the sport's "older days" to its modern form. Particularly from 2006 to 2013, St-Pierre represented everything mixed martial arts was looking for. He was essentially perfect in those years, winning 14 of 15 bouts, including 12 title fights. At one point, he won 33 consecutive rounds. He was solely responsible for an explosion of fan interest in Canada and was one of the promotion's biggest stars globally. His style was ahead of its time, known for blending a variety of skills seamlessly together. He is also remembered as one of the most outspoken critics of performance-enhancing drugs during his era. -- Brett Okamoto
3. Anderson Silva
Key accomplishments: UFC middleweight champion, UFC record holder for most consecutive wins (16), UFC Hall of Fame
Arguably the most iconic fighter in mixed martial arts history. Silva represented nothing short of greatness during his UFC tenure, which spanned from 2006 to 2020. He won the UFC title in his second Octagon appearance in 2006, and went on to have one of the best careers the sport has ever seen. It wasn't just Silva's record, which was perfect in the UFC for seven years straight, it was the way in which he carried himself and dispatched of his opponents. He had some of the most impressive finishes the sport has seen: Rich Franklin via knee strikes, knocking out Forrest Griffin with a jab, submitting Chael Sonnen in the fifth round of a fight he was losing and the front kick knockout of Vitor Belfort. Silva was like something out of a movie during his long middleweight reign. He is one of the most beloved figures in the game. -- Okamoto
4. Demetrious Johnson
Key accomplishments: Current One Championship flyweight champion, Inaugural UFC flyweight champion, most consecutive title defenses in UFC history (11), most wins in UFC flyweight title fights (12), most submissions in UFC title fights (five)
Although he hasn't fought in the UFC in nearly seven years, Johnson's name is still littered all throughout the promotion's history books. He's arguably the fastest MMA fighter in history, with an outstanding combination of wrestling and striking that left his opponents in the dust. He was so dominant during his run as flyweight champion from 2012 to 2018 that the promotion considered shuttering the division. Instead, they sent him to One Championship thinking his best years were behind him and made a horrible miscalculation as "Mighty Mouse" is still thriving as one of the best to ever do it. At 37 years old, he looks rejuvenated and continues to add to his legacy in One Championship as their current flyweight champion. -- Hale
5. Khabib Nurmagomedov
Key accomplishments: UFC lightweight champion with longest reign in division history (1,077 days) and tied for most title defenses (three); tied for most submission wins in title fights, any division (three); most takedowns in a UFC fight (21 vs. Abel Trujillo in 2013); UFC Hall of Famer
There's no such thing as a perfect fighter, but Nurmagomedov was the rare mixed martial artist to finish a career with a perfect record. He was 29-0 and the UFC lightweight champion when he abruptly retired in October 2020 at age 32, citing a promise he made to his mother following the death of his father and lifelong coach earlier that year from COVID-19 complications. The UFC made several attempts to get Nurmagomedov back into the cage -- in MMA, fighter retirements rarely stick -- but he has moved on to coach others, including current lightweight champ Islam Makhachev.
Nurmagomedov was something of a throwback as a fighter, in that he utilized a single skill -- wrestling -- and veered into other disciplines only to set up his wrestling. Nurmagomedov was relentless in pursuit of takedowns, pressuring his opponent toward the cage, where he would then take him to the canvas, trap his legs to all but eliminate the possibility of escape, then either finishing the opponent or dominating him to the final horn. Nineteen of his 29 wins came by either submission (11) or KO/TKO (8). Nurmagomedov was unstoppable. -- Jeff Wagenheim
6. Fedor Emelianenko
Key accomplishments: Pride heavyweight champion, went unbeaten in 28 consecutive fights
The original GOAT. During the peak of Pride Fighting Championship's popularity in the early 2000s, Emelianenko established himself as the gold standard of mixed martial arts. He had an air of invincibility during that time, defeating opponents from all over the planet and from every discipline, including names like Antonio Rodrigo Nogueira, Mark Coleman, Kevin Randleman, Mirko Cro Cop and Mark Hunt. He was a primary target of the UFC and Dana White for years, but a deal between the two sides ultimately failed to come to fruition. The mystique of Emelianenko, especially during his peak, is essentially its own chapter of MMA history. -- Okamoto
7. Randy Couture
Key accomplishments: Three-time UFC heavyweight champion, two-time UFC light heavyweight champion, first multi-division champion in UFC history, most championship reigns in UFC history (six), oldest fighter to be UFC champion (45 years, 60 days), oldest fighter to win a bout in UFC history (47 years, 68 days), UFC Hall of Famer
Although a look at his record may not suggest it to the new generation of fans, Couture is far and away one of the greatest fighters to ever compete in the sport of MMA. "The Natural" spent the majority of his 14-year career competing in title fights and is widely recognized as the first great heavyweight in MMA, known for using his outstanding Greco-Roman wrestling pedigree to pin his opponents to the mat and unleash ground and pound. Couture's most significant run took place from 2000 to 2004 when he captured the heavyweight title and later grabbed the light heavyweight championship while engaging in memorable wars with Tito Ortiz and Chuck Liddell in what could be described as MMA's golden era that helped establish the UFC's presence in the United States. -- Hale
8. Chuck Liddell
Key accomplishments: UFC light heavyweight champion; most knockouts in division history (10) and longest knockout streak in UFC history (seven); tied for most knockdowns in UFC light heavyweight history (14) and tied for most consecutive fights with a knockdown (seven); 2009 inductee into UFC Hall of Fame.
The distinctive mohawk and Fu Manchu made Liddell stick out in a crowd, even among the fiercest-looking MMA fighters. But what distinguished Liddell even more was the nonstop attack with his fists, which often led to an explosive celebration with the opponent woozy on the canvas. Even beyond his fistic prowess, "The Iceman" was an influential figure. He coached opposite another legend, Randy Couture, on the first season of "The Ultimate Fighter," and that reality TV show helped save the UFC from going out of business.
The TV time also launched Liddell's ascent into becoming MMA's first crossover star. He had one of the most memorable cameos during the popular run of HBO's "Entourage" and Liddell also acquitted himself surprisingly well on ABC's "Dancing with the Stars." The latter showed a side of the fighter that was far different from the guy who left his Octagon opponents seeing stars. -- Wagenheim
9. BJ Penn
Key accomplishments: UFC lightweight and welterweight champion, second UFC fighter to ever win titles in multiple weight classes
Penn's legacy consists of two major components. He was widely considered the greatest lightweight of all time, until Nurmagomedov's 29-0 career. More so than that, however, he was the original poster boy for fighting outside of his weight class. Penn was a natural-born fighter, with a Hawaiian spirit. The majority of his early career saw him pitted against bigger men, including an infamous matchup in 2005 in Japan when he fought 225-pound, future UFC light heavyweight champion Lyoto Machida. At the climax of his career in 2009, he was a candidate for best pound-for-pound fighter in the world. -- Okamoto
10. Kamaru Usman
Key accomplishments: UFC welterweight champion, The Ultimate Fighter 21 tournament winner, most consecutive wins in UFC welterweight history (15), First Nigerian-born UFC champion
While St-Pierre is recognized as the greatest welterweight in UFC history, Usman was nipping at his heels during a phenomenal tear from 2018 to 2021. Usman went from wrestler to full-fledged mixed martial artist during this time, capturing the welterweight title by defeating Tyron Woodley and looked nearly indestructible during his championship reign with dominant victories over Jorge Masvidal, Colby Covington and Gilbert Burns. With an outstanding résumé that saw him ascend to become the No. 1 pound-for-pound fighter on the UFC rankings during his magnificent run, Usman still has time to add to his legacy before it's all said and done. -- Hale