Rick John Roufus is a retired American kickboxer. He has also competed professionally in boxing and mixed martial arts. An accomplished professional fighter throughout his competitive career, Roufus has won multiple world championships across the globe in several weight classes, he was world champion as a super middle weight, light heavyweight and heavyweight. Roufus held titles for all the major kickboxing associations worldwide, and is known for his boxing skills and powerful kicks. He is the older brother of Duke Roufus who is also a kickboxer and a Muay Thai and mixed martial arts instructor. Rick Roufus is the Global Director of Fighter Development for PKA Worldwide. In 2012 Rick Roufus was inducted into the World Kickboxing League Hall of Fame.
Adam Keith Watt is an Australian martial artists, former boxer and kickboxer. He has studied many forms of martial arts, kickboxing, Zen Chi Ryu, Seido-kaikan karate, and boxing. His nickname was "Lights Out" because of his high level karate and boxing skills, and one punch knock out power. He has won many world kickboxing titles, and reached as high as 10th in the highly respected World Boxing Council's & World Boxing Organisation's Cruiserweight ratings. In 2000, he challenged WBO cruiserweight champion Johnny Nelson for his title. Watt holds the notable distinction of being the first athlete to fight for world Karate, kickboxing and boxing titles.
Jörgen Ingmar Kruth is a retired Swedish professional kickboxer and mixed martial artist. He is a former two time World Muay Thai Council Heavyweight Muaythai World Champion. He is considered to be among the greatest Scandinavian kickboxers of all time.
Ray Sefo is a New Zealand fight promoter and retired kickboxer, boxer, and mixed martial artist. He was the K-1 World Grand Prix 2000 Runner-up, is a six-time Muay Thai World Champion, and was an eight time K-1 World Grand Prix Finals tournament participant. He is the president of MMA promotion Professional Fighters League. In kickboxing, he defeated world champions Jerome Le Banner, Peter Aerts, Stefan Leko, Mike Bernardo, and Mark Hunt. He is widely considered to be one of the greatest heavyweight kickboxers to have never won the K-1 World Grand Prix. As mixed martial artist, he most notably competed in the now defunct Strikeforce in 2009 and 2011.
Jérôme Philippe Le Banner is a French kickboxer, mixed martial artist, and professional wrestler. Le Banner fought for most of his career in K-1 and became known for his aggressive fighting style and knockout power. He is a 2-time K-1 World Grand Prix runner up, a 2-time K-1 Preliminary Grand Prix champion, and is a multiple time world champion in Kickboxing and Muay Thai. He holds notable victories over Ernesto Hoost (twice), Francisco Filho, Mark Hunt, Sam Greco, Mike Bernardo (twice), Peter Aerts, Rick Roufus, Remy Bonjasky, Tyrone Spong, Stefan Leko (twice), Masaaki Satake, Maurice Smith, Gary Goodridge (twice), Musashi (twice), Cyril Abidi and Choi Hong-man (twice).
James Warring is an American boxer, kickboxer and mixed martial artist. In professional boxing, he held the IBF world cruiserweight title from 1991 until 1992. In kickboxing, Warring is a four-time world champion, which included WKA world titles in 1983 and 1989. Warring alog with Troy Dorsey are the only two fighters to hold World titles in both Boxing and Kickboxing simultaneously although Warring held Kickboxing titles on the international rules level.
Robert Diem Kaman was a Dutch nine-time kickboxing and Muay Thai world champion. He was often called "Mr. Low Kick" because of his feared low kicks which he used to set up his devastating offensive attacks.
Nathan "Carnage" Corbett is a New Zealand-born Australian former Muay Thai kickboxer, who has held 11 world titles in three weight-divisions.
Changpuek Kiatsongrit is a Thai former Muay Thai fighter. He is credited as being one of the first Muay Thai fighters to go abroad and fight other fighters of other martial arts styles, often stronger and heavier than himself, bringing to the world an understanding of the effectiveness of Muay Thai. Changpuek is a seven time world champion who has fought some of the world's best fighters at middleweight to heavyweight and has wins against world class fighters such as Rob Kaman (x3), Rick Roufus, Peter Smit and Tosca Petridis. After ending his career as a professional fighter while working for Sitpholek gym in Pattaya, Thailand, he continued his employment at that gym as a Muay Thai trainer.
Peter "The Hurricane" Smit was a Dutch martial artist who mastered such different fight disciplines as kyokushin karate, kickboxing and Muay Thai.
Dale Cook is an American former kickboxer who competed in the middleweight, super middleweight, light heavyweight and cruiserweight divisions. With a background in karate and taekwondo, Cook debuted professionally in 1977 and spent the early part of his career as a full contact rules fighter. In the 1980s, he began fighting under Oriental and Muay Thai rules and took two world titles under the WKA banner. A short stint in shoot boxing towards the end of his career in the mid-1990s resulted in another world title in that discipline.
Paul "The Sting" Slowinski is a Polish kickboxer, a four-time World Muay Thai Council (WMC) Muay Thai World champion and two-time K-1 World GP 2006 in Auckland and K-1 World GP 2007 in Amsterdam champion. After two years training in Amsterdam, Netherlands under Ernesto Hoost, Slowinski moved back to Adelaide in 2009 and began to teach and train out of Rikers Gym. He has competed in the K-1 and SUPERKOMBAT promotions.
Tyrone Clinton Spong is a Surinamese-Dutch professional boxer and mixed martial artist and former kickboxer. As a boxer, he held the WBC and WBO Latino heavyweight titles in 2018. In kickboxing, he is the former WFCA cruiserweight champion, Glory 95kg Slam Champion and It's Showtime 95MAX World champion.
John Wayne "The Gunslinger" Parr, also known as JWP, is a retired Australian Muay Thai fighter, kickboxer and boxer, fighting out of Boonchu Gym in Gold Coast, Queensland. He is a former 10-times World Champion and was the runner up on The Contender Asia.
Eduardo "Morpheus" Maiorino was a Brazilian professional kickboxer and mixed martial artist. He was a three time Brazilian Heavyweight Muay Thai Champion, the K-1 Brazil 2004 Tournament finalist and champion, and a World Muay Thai Association (WMA) Super Heavyweight World Champion.
K-1 Grand Prix '93 was a martial arts event held by the K-1 organization on April 30, 1993, at the Yoyogi National Gymnasium in Tokyo, Japan. It was the inaugural K-1 World Grand Prix, featuring an eight-man tournament fought under K-1 rules. The eight tournament qualifiers were all invited on the basis of their achievements in the kickboxing world. As well as tournament matches there was also a full contact karate bout between Andy Hug and Nobuaki Kakuda. The event featured ten fights with fighters representing seven countries. The winner was Branko Cikatić who defeated Ernesto Hoost in the final by first-round knockout, becoming the first K-1 World champion.
Manson Howard Gibson is a retired American kickboxer and a 12-time world champion in kickboxing and Muay Thai. He was known for his vicious use of spinning techniques and wild, unpredictable style, mixing elements of kickboxing, Taekwondo and Northern Praying Mantis martial arts. He was sometimes referred to as the "Thai Killer" or the "Black Bruce Lee". Gibson was one of America's greatest kickboxers, and is credited with over 100 wins and more than 80 KOs, including around 40 via headkick.
Anthony "Antz" Nansen is a New Zealand professional boxer, kickboxer, mixed martial artist.
Dennis Alexio vs. Branko Cikatić was a heavyweight kickboxing bout that took place at the Thomas & Mack Center in Las Vegas, Nevada, US, on March 16, 1992, which ended in a controversial technical draw.
Krongsak Sakkasem is a Thai former Muay Thai fighter and kickboxer.
Ernesto Hoost 
Changpuek Kiatsongrit 
Toshiyuki Atokawa 
Jean-Yves Thériault 