The name "Big John" McCarthy is synonymous with the history of the Ultimate Fighting Championship (UFC), representing the gold standard of mixed martial arts (MMA) officiating. As of December 2025, the legendary referee is back in the cage, a surprising development for fans who saw him transition into a long-term role as a color commentator and media personality. This return, coupled with his recent expiration of a PFL contract and his outspoken criticism of the UFC's current officiating standards, makes him one of the most talked-about figures in combat sports today.

McCarthy's influence extends far beyond simply breaking up fights; he was instrumental in creating the sport's foundational rule set, the Unified Rules of Mixed Martial Arts. His recent activities—including a return to refereeing combat sports like A1 Combat 32 and his candid commentary on the Weighing In podcast—provide a fresh, insider perspective on the controversial state of MMA. This deep dive uncovers the latest truths about the man who literally wrote the book on MMA refereeing and his current, complex relationship with the sport he helped build.

John "Big John" McCarthy: Complete Biography and Profile

John Michael McCarthy, universally known as "Big John," is perhaps the most recognizable and respected figure to ever step inside an MMA cage as an official. His imposing presence, combined with his deep understanding of martial arts and law enforcement, made him the definitive authority during the UFC's formative, chaotic years.

• Full Name: John Michael McCarthy
• Nickname: Big John
• Date of Birth: October 12, 1962
• Place of Birth: Los Angeles, California, USA
• Height: 6 ft 3 in (192 cm)
• Career Start: First-ever referee in the Ultimate Fighting Championship (UFC 1, 1993)
• Former Professions: Los Angeles Police Department (LAPD) officer, SWAT team member, Self-Defense Instructor.
• Key Contribution: Instrumental in developing the Unified Rules of Mixed Martial Arts.
• Post-Refereeing Roles: Color Commentator/Analyst for Bellator MMA and Professional Fighters League (PFL), Co-host of the Weighing In podcast.

McCarthy's background as a police officer and a former SWAT team member gave him a unique combination of authority and de-escalation skills, traits that were essential in the no-holds-barred environment of early UFC events. He was personally asked by UFC co-founder Rorion Gracie to officiate the inaugural event, UFC 1, cementing his place in history from the very beginning. His journey from the Octagon to the broadcast booth and back to the cage is a testament to his enduring commitment to the integrity of combat sports.

The Undeniable UFC Legacy: Architect of the Unified Rules

The history of the UFC cannot be told without acknowledging John McCarthy's pivotal role in its survival and eventual mainstream success. When the sport was derided as "human cockfighting" and faced legislative bans, McCarthy was one of the driving forces for structure and safety.

His most significant and lasting contribution is his work on the Unified Rules of Mixed Martial Arts. These rules, which standardized the sport across North America and beyond, were largely based on the rules he developed and enforced during his early years with the UFC. The rules defined weight classes, codified legal and illegal techniques, and established the scoring criteria that judges use to this day. Without this framework, MMA would likely have remained a fringe spectacle, unable to gain sanctioning from state athletic commissions.

McCarthy's tenure as the premier UFC referee saw him officiate nearly every major milestone fight from the 1990s through the 2000s, including bouts featuring legends like Chuck Liddell, Randy Couture, and Georges St-Pierre. His signature phrase, "Let's get it on!" became an iconic part of the UFC's pre-fight ritual. His ability to command respect from fighters and manage the intensity of the cage earned him the moniker "Big John" and made him the benchmark for all future MMA officials.

However, McCarthy's relationship with the UFC became strained over time, particularly as the promotion grew under the leadership of Dana White. In 2008, he announced his first retirement from officiating, citing a desire to spend more time with his family and pursue other opportunities. While he returned for a second stint, he eventually moved away from the promotion entirely to take on a role as a color commentator for Bellator MMA in 2018, and later worked with the Professional Fighters League (PFL), signaling a clear distance from the UFC's inner circle.

The 2025 Shock: Return to Officiating and Explosive UFC Critiques

The most recent news surrounding John McCarthy in late 2024 and 2025 centers on two major developments: his surprising return to active refereeing and his increasingly vocal criticism of the current state of MMA officiating, particularly within the UFC.

The Return to the Cage and PFL Departure

In a move that stunned the MMA media landscape, McCarthy announced he was stepping away from his media commitments, including his popular Weighing In podcast, which he co-hosts with former fighter Josh Thomson. The reason for this shift was both personal and professional. McCarthy revealed he had been dealing with physical issues, including a significant neck injury that caused temporary paralysis and forced him to stop training Brazilian Jiu-Jitsu (BJJ).

Despite these health challenges, McCarthy announced his return to officiating combat sports, taking on assignments with promotions like A1 Combat 32. He explained that stepping back into the cage as a referee was less physically demanding than the constant travel and media appearances required for his analyst and podcast roles. This decision marks a full-circle moment for the veteran official, allowing him to focus on the technical side of the sport he loves.

Furthermore, his contract with the PFL, where he served as a commentator, recently expired. While he has expressed a desire to continue working in MMA, his focus has clearly shifted back to the role of an official and a rules analyst, a position he believes is sorely needed in modern broadcasts.

The Controversial State of Modern MMA Refereeing

McCarthy's return to the cage has coincided with a renewed focus on his commentary regarding judging and refereeing controversies. Using his platform on the Weighing In podcast, McCarthy has been an explosive critic of several high-profile UFC decisions in late 2024 and 2025.

One notable instance involved his sharp critique of a referee's stand-up decision during a fight at UFC 316. McCarthy argued that the official was too quick to separate the fighters, intervening prematurely and robbing a competitor of a dominant position. He has repeatedly stressed that the current crop of officials often lacks the necessary experience or understanding of grappling to make correct, timely decisions, leading to unnecessary controversy and impacting fight outcomes.

McCarthy's core argument is that the UFC needs to incorporate a dedicated "rules analyst" into its broadcast team—a role he would be perfectly suited for—to provide immediate, expert analysis on controversial calls to the audience. He maintains that this transparency is crucial for the sport's credibility, especially as judging and refereeing errors continue to dominate post-fight discussions. His recent actions and statements solidify his position not just as a legend, but as an active, critical voice pushing for higher standards in combat sports officiating, both inside and outside the Octagon.