UFC, OBJ and RBI are among the well-known abbreviations in sports today.

KSI has stormed onto the scene as one of pop culture's biggest headline makers of the past few years. And he's elbowing his way into the sports landscape.

He will face boxer and reality television star Tommy Fury in an exhibition boxing match on Saturday in a co-headlining fight with Logan Paul and MMA star Dillon Danis.

With a reported net worth of $23.9 million, KSI has made his name as one of the most prominent social media stars of the digital age. He has more than 24 million YouTube subscribers, 13 million Instagram followers and 11.7 million followers on TikTok as fans clamor to keep up with his content. As a rapper, he has a No. 1 album in the United Kingdom. As a businessman, he has one of the fastest-growing beverage companies in the world.

Who is KSI?

KSI is a YouTuber-turned-boxer, musician and entrepreneur.

Born Olajide "JJ" Olatunji, he rose to fame off FIFA video game commentary, which he first posted to his YouTube channel in 2011. He adopted the "KSI" name to become a part of a "Halo" clan and is part of the creative collective "Sidemen."

The 30-year-old was born in London to Nigerian parents. He has a younger brother, Deji, who is also popular on YouTube and has his own boxing career.

KSI is known for his flashiness — he will be wearing a $50,000 mouth guard for his fight against Tommy Fury — and brazen personality. When he was rising in popularity, he received criticism for misogynistic content on his YouTube page and this spring, he was called out for using a racial slur in a video, which he apologized for.

What is KSI's boxing history?

KSI (5-0-1) made his boxing debut in 2018 with a knockout of fellow YouTuber Joe Weller. Later that year, he had a draw in an amateur match against another YouTube star, Logan Paul. The two had a rematch in 2019, which KSI won by decision.

Fighting as a cruiserweight, KSI has had three straight knockouts, including January's takedown of esports giant Thomas Oliveiram aka FaZe Temperrr.

KSI initially won his May fight against fellow British boxer and nightlife entrepreneur Joe Fournier, but it was declared a no contest after review showed that KSI illegally elbowed Fournier.

KSI is friends with former heavyweight champion Anthony Joshua, who has been rumored to fight Fury's older brother Tyson, but the match never materialized.

"Everyone is thinking that I have no chance. I'm the underdog," KSI told Joshua in his YouTube documentary ahead of the Tommy Fury fight. "It's mainly because I have no right to be in the ring with him. He's been boxing for how long? And I've been doing it for way less years. So for me to then go in the ring with him and knock him out, it would be like, bro."

He also co-founded Misfits Boxing in 2021, a promotional company that celebrates the crossover of entertainment and sport. KSI has put on his own fights through the brand, including the Fury fight.

Who is KSI the rapper?

KSI also has a career as a rapper. He's released music commercially since 2015, including two solo albums. His 2021 LP "All Over the Place" went No. 1 on Great Britain's Official Albums Chart, selling 34,000 units its first week, including 20.9 million streams.

"I’ve been doing music for so long and to finally get this is crazy," KSI said at the time. "Official Charts Company. Number 1. I never thought I’d ever get one of these. I have no right – I’m a YouTuber!

He's gotten features from the likes of Tion Wayne, Bugzy Malone, Rick Ross, Lil Baby, Trippie Redd and Lil Wayne.

His music intertwines with his social media and boxing careers as he made diss tracks to Joe Weller and Logan Paul leading up to their fights.

What is KSI's relationship to Logan Paul?

KSI and Logan Paul were bitter enemies in the late 2010s and they fought each other in a 2018 boxing match. The first face-off was a draw, but KSI won the 2019 rematch.

The foes-turned-friends now own PRIME, a beverage competitor to Gatorade and Powerade. They introduced the drink in 2022 and advertised it as a healthier alternative with less sugar.

PRIME comes in fun flavors like Ice Pop, which is reminiscent of Bomb Pop popsicles, and the newly-released Glowberry.

The company has replaced Gatorade as the official hydration partner of FC Barcelona and also is the sports drink sponsor of Arsenal FC and the Los Angeles Dodgers. They sponsor athletes as well, including soccer player Alisha Lehmann and UFC fighters Israel Adesanya and Alexander Volkanovski.

The duo are leaders of a marketing movement to engage the younger generation through digital content and controversy.