Ronaldo "Jacaré" Souza "Jacaré"

Ronaldo Souza dos Santos, known throughout his career by the nickname "Jacaré" — Portuguese for alligator, earned for his aggressive, relentless style on the mat — was born on December 7, 1979 in Vila Velha, in the Brazilian state of Espírito Santo. He built his black belt under instructor Henrique Machado, receiving it in 2003, and quickly validated the promotion with one of the more dominant multi-year runs of the sport's mid-2000s era. In his ADCC debut in 2003, he won gold at the South American trials before taking silver at -88kg in the ADCC World Championship that same year; two years later, at the 2005 ADCC World Championship, he claimed gold at -88kg outright and added a silver medal in the openweight absolute division, losing only to Roger Gracie in that final.

Across 2004 and 2005, Souza layered IBJJF success on top of his ADCC results, winning World Jiu-Jitsu Championship gold at black belt, a Pan American Championship title, and a European Open Championship — the kind of resume that made him one of the most feared grapplers in his weight range anywhere in the world at that time. His single most prestigious individual result may be his 2009 win in the ADCC Superfight Championship, a standalone, high-profile match for the vacant title in which he defeated fellow Brazilian standout Robert Drysdale.

Souza's transition into mixed martial arts began around 2007, and he built a long, successful career that ran through Strikeforce, where he won the middleweight championship, and then the UFC, where he competed from 2013 until his release in 2021 following a string of losses against elite middleweight and light-heavyweight competition. Across 37 total professional MMA bouts he won 26 and lost 10, a rate reflecting how directly his grappling pedigree carried over into the cage, even against opponents who trained specifically to survive against a black belt of his caliber. He officially announced his retirement from MMA in August 2021, closing out an 18-year professional run, and made a single boxing exhibition appearance in 2023, a loss to Vitor Belfort.

In the years since stepping away from active competition, Souza has continued to run his own jiu-jitsu academy and coaching operation, and in 2024 he was formally inducted into the ADCC Hall of Fame in recognition of his title run through the mid-to-late 2000s, an honor reserved for a small group of competitors considered foundational to the event's history. As of 2026 he is alive, active in coaching, and a regular presence in grappling and MMA media retrospectives covering his career. His legacy sits at the intersection of two disciplines: inside pure jiu-jitsu circles he is remembered as one of the most explosive top-pressure grapplers of his generation, while in MMA he is remembered as one of the clearest examples of a jiu-jitsu specialist translating that skill set into a decade-plus of top-level professional competition.

Explosive top-pressure passing and takedown-driven control that produced a high finishing rate in both grappling and MMA