There are nicknames, and then there are identities. For Brendan Allen, ‘All In’ isn’t just a catchy phrase for Bruce Buffer to announce before his fights; it’s a reflection of how he lives, trains, and fights. Currently ranked no. 9 in the UFC middleweight division, Allen has built his career on a single principle: no half measures. 

Now set to face Reinier de Ridder in the main event at UFC Vancouver on October 18, 2025, replacing Anthony Hernandez, Allen is once again walking the path he knows best, the one that demands complete commitment. But where did this name come from? And why does it fit him so perfectly? Let’s dig into the meaning behind the moniker that defines his fighting spirit!

How Did Brendan Allen Earn the Nickname ‘All In’?

“I’m just me.” That’s what Brendan Allen once told the UFC. And maybe that’s exactly what makes him unstoppable. The nickname “All In” wasn’t given to him by a coach or a fight promoter; it came long before his UFC days. In fact, it started when Allen was just 16 years old. He once shared that, “My friend Ben Peco gave it to me when I was about 16.”

It stuck. And looking at his career, it’s hard to find a more fitting name. ‘All In’ not only rhymes with “Allen,” but it perfectly mirrors the way he approaches everything, whether it’s training, fighting, or life itself.

From the beginning, Allen’s fighting style has reflected his nickname. Aggressive, relentless, and willing to risk it all, he embodies the idea of a man who refuses to hold back. His grappling-heavy style, known for dangerous rear-naked chokes and slick transitions, is built around constant pressure. 

Out of his 13 wins inside the Octagon, 7 have come via submission, giving him a stunning 54% submission rate. And that mentality goes far beyond technique. It’s about mindset. It’s about the way he fights through pain and setbacks, refusing to fold when things get tough.

Which Fights Best Show Brendan Allen’s All-In Attitude?

Allen puts everything on the line when he steps inside the octagon and is not afraid to take high-risk chances. His downplaying of the knee injury during his fight with Paul Craig is an example of his grit. Allen had his sixth straight win by tapping out Paul Craig with a rear-naked choke in UFC Vegas 82’s main event, but not without sustaining damage himself. 

“I wasn’t expecting him to go for my legs,” Allen said during the UFC Vegas 82 post-fight presser. He casually stated that he could feel “things were popping”. Allen downplayed his injury, stating, “Again, I’ve been in a lot of positions like that. I’ve been popped in tournaments and stuff like that growing up, so I knew there was nothing left as far as extension-wise. So I was fine, but it’s a little sore right now.”

Born to Michelle and James Allen of Louisiana on December 28, 1995, Allen’s career in MMA began when he saw his elder brother taking a Jiu-Jitsu class. The young man decided to join the same academy to train himself in BJJ at 13. Apart from that, Allen gives credit to UFC events for his interest in combat sports, “I watched UFC on TV while I was playing football,” Allen told MMASucka.

He further added in the interview that his brother was the catalyst for his interest in MMA. “One day my brother’s friend offered to come try a class. So, my dad, brother, and I did, and I signed up right then. It’s history from there,” he said.  He also had a degree in Criminal Justice, but his true calling was always MMA. 

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After some fights in other promotions, he was finally signed with the UFC when he defeated Aaron Jeffery in the Dana White’s Contender Series. Since then, he’s faced tough opponents, including Marvin Vettori, whom he beat earlier this year at UFC 318. Each fight reinforced the same message: win or lose, Brendan Allen never holds anything back.