Olajide Olayinka Williams Olatunji (also known as KSI) was born in London on June 19, 1993. He was brought up in Watford, Hertfordshire.
His mother Yinka Atinuke is from London’s Islington. He is of Yoruba ancestry, as are his parents.
KSI attended Berkhamsted School in Berkhamsted. This is where he met Simon Minter, a future partner and member of the Sidemen.
Deji Olatunji is the younger brother of KSI, and he is a YouTuber as well.
Still in his early teens, KSI created his first YouTube channel under the nickname ‘JideJunior’ in 2008. In July 2009, he opened a channel on YouTube under the username KSIOlajideBT. This is where he posted gaming-commentary videos of the FIFA video game series from his bedroom in England. His name KSI stands for ‘Knowledge Strength Integrity’.
KSI signed with Polaris in October 2013. The group produces internet videos that often include challenges, comedy, and video-game commentary.
In 2015, KSI released his autobiography named ‘KSI: I Am a Bellend’. The book was published in September 2015 in the UK.
KSI announced on Twitter on August 4 that he was quitting the Sidemen due to disagreements with fellow member Ethan Payne. Soon after, he began to insult his former band’s members in a series of videos.
The Times named KSI as Britain’s top influencer in 2020.
After beginning to write and create comedy-rap songs for his YouTube channel in 2011, KSI collaborated with Dcypha Productions to release his first single. It was named ‘Lamborghini’ and was released in March 2015. The song peaked at number 30 on the UK Singles Chart.
KSI released his song ‘Voices’ featuring Oliver Tree in January 2023. He collaborated on the song ‘Easy’ with Bugzy Malone and R3HAB. The song was used as the ring walk soundtrack for his match against Joe Fournier that same night.
Around the end of 2017, KSI and British YouTuber Joe Weller allegedly started having hostilities. The two declared that they will arrange an amateur boxing bout at Copper Box Arena in London to end their dispute after having conflicts on Twitter and diss-tracks.
KSI won the match within 1 minute and 37 seconds into the third round. After the bout, KSI commended Weller for his dedication to spreading awareness about mental health and called out American YouTuber Logan Paul, his brother Jake Paul, and former footballer Rio Ferdinand.
In February 2018, it was revealed that KSI and Logan Paul will square off in an amateur boxing match. Two judges scored the bout evenly at 57-57, while a third judge scored it 58-57 in favour of KSI. The match thus resulted in a majority draw.
Eddie Hearn promoted a rematch between KSI and Paul on November 9, 2019. The event took place at the Staples Centre in Los Angeles. Floyd Mayweather Jr.’s uncle Jeff Mayweather and professional boxer Viddal Riley trained KSI. KSI won the match against Paul by a split decision. Two judges scored the bout in favor of KSI at 56-55 and a third scored in favor of Paul at 57-54.
KSI next competed against Brazilian YouTuber and FaZe Clan founder FaZe Temperrr in order to defend his MF cruiserweight title. KSI ended up winning the match and retaining his title with a first-round knockout victory over Temperr.
KSI competed against professional boxer Joe Fournier on May 13, 2023. The match took place at London’s Wembley Arena. In the match, KSI defeated Fournier via KO in the second round.
After video replays revealed that KSI had used an illegal elbow strike during the closing move, a debate erupted regarding KSI’s retention of his MF cruiserweight championship. The Professional Boxing Association requested that both combatants present their arguments after Fournier challenged the judgement on May 15. The Professional Boxing Association declared the match a no-contest on May 19.
KSI and Wasserman Promotions announced their collaboration to start the boxing promotion ‘Misfits Boxing’ in June 2021.
‘KSI: Can’t Lose’ was a documentary movie released in 2018 by KSI. The documentary explores the circumstances around how KSI defeated fellow YouTuber Joe Weller to win his boxing debut match and how KSI will use what he learned to defeat Logan Paul. The movie was made by Sony Pictures Home Entertainment and co-created by YouTuber Callux’s After Party Studios.
A video game called KSI Unleashed was released for iOS and Android devices in 2016. It was a collaboration between KSI and Endemol Shine Group.
In 2018, Sidemen collaborated with True Geordie and Viker Limited to create the iOS and Android video game BoxTuber. The game has a variety of YouTubers that the player can battle with. It was released in order to promote the KSI vs. Logan Paul boxing event. BoxTuber reached the top of the UK iTunes rankings 24 hours after the game’s debut.
In 2018, KSI practised with former UFC middleweight champion Michael Bisping as part of the marketing for EA Sports UFC 3.
KSI and Logan Paul announced in January 2022 that they had founded Prime, a beverage company. The Prime brand consists of a variety of sports drinks, drink mixes, and energy drinks that Prime Hydration, LLC develops and promotes.
At WrestleMania 39 in April 2023, KSI made a cameo during the match between Logan Paul and Seth Rollins. He accompanied Paul during his entrance while dressed as a Prime bottle. However, Paul frog-splashed him after Rollins swiftly swapped him out for KSI.
In 2015, KSI contributed $10,000 to a YouTuber named Castro1021’s online charity broadcast. He also took part in the Race Against Slime event to raise money for the SpecialEffect organisation, which creates technologies to make video games more accessible for people with physical disabilities.
KSI recently adopted a cat named Buu.