KSI is one of the biggest names to come out of YouTube. He started as a teenager posting gaming videos, then grew into a rapper, boxer, and businessman. Today he is known for the Sidemen, his music, big boxing nights, and drinks brand Prime. His real name surprises a lot of new fans.
Who is KSI?
KSI is a British internet star who has done a bit of everything. He began by uploading FIFA gameplay videos back in 2009 and quickly built a huge following.
Over the years he moved into music, comedy, and boxing. He co-founded the popular YouTube group the Sidemen and later helped launch Prime Hydration with Logan Paul.
He is also a former professional boxer who fought under the ring name “The Nightmare.” In 2026, he joined Britain’s Got Talent as a judge.
| Detail | Information |
|---|---|
| Full Name | Olajide Olayinka Williams Olatunji |
| Nickname | JJ / The Nightmare |
| Profession | YouTuber, Rapper, Former Boxer, Entrepreneur |
| Date of Birth | 19 June 1993 |
| Age | 33 years (as of 2026) |
| Birthplace | London, England (raised in Watford) |
| Nationality | British |
| Zodiac Sign | Gemini |
| Ethnicity | Nigerian (Yoruba) descent |
| Known For | Sidemen, YouTube, Prime Hydration, Boxing |
KSI Real Name
A lot of people only know him as KSI, but that is not his birth name. His real name is Olajide Olayinka Williams Olatunji. Friends and family usually just call him JJ.
The name “KSI” actually came from his gaming days. It stands for Knowledge, Strength, and Integrity, which he explained in an early video on his channel.
His first online handle was even longer. He started with “JideJunior” in 2008, then created the “KSIOlajideBT” account in 2009. The “BT” part came from British Telecom, so his early username mixed his gaming tag, his real name, and his internet provider.
KSI’s Height, Weight and Physical Appearance
| Attribute | Detail |
|---|---|
| Height | 6 feet 0 inches (183 cm) |
| Weight | Around 88 kg (cruiserweight) |
| Eye Color | Dark Brown |
| Hair Color | Black |
| Body Type | Athletic |
KSI has a tall and strong build, which fits well with his boxing background. During his fights he competed at cruiserweight, weighing close to 88 kg.
He stands at about six feet, giving him a solid frame in the ring. His training over the years helped him build a lean and muscular body.
Off camera, he keeps a simple look with short black hair and dark brown eyes. His energetic personality often stands out more than his appearance.
Background and Early Life
KSI was born on 19 June 1993 in London, England, and grew up in Watford, Hertfordshire. He comes from a Nigerian family with Yoruba roots.
He went to Berkhamsted School, a private school in England. It was there that he met Simon Minter, who later became a Sidemen member alongside him.
As a teenager, KSI loved playing FIFA and started recording his gameplay. His passion for YouTube grew so much that he eventually dropped out of education to focus fully on his online career.
Is he married? Who is KSI’s Wife or Partner?
KSI is not married. He has always been very private about his love life and rarely shares details with the public.
In past interviews, he confirmed that he had a girlfriend but chose to keep her out of the spotlight. He once said on Good Morning Britain that he likes to keep personal things quiet.
During his early rise to fame, he dated his high school sweetheart, Seana Cuthbert, but the two split in 2014. As of 2026, his current relationship status is kept private, and he has not publicly confirmed a partner.
Family Background
KSI comes from a close Nigerian-British family. His mother is named Yinka, and his father is Jide Olatunji. His parents raised him with strong values, and he often speaks about the drive that came from his immigrant family background.
He has a younger brother named Deji Olatunji, who is also a well-known YouTuber and boxer.
The brothers had a public fallout years ago, including a moment when Deji shared KSI’s private bank details online. They have since made up, though their relationship has had its ups and downs.
KSI’s Net Worth 2026
| Year | Estimated Net Worth |
|---|---|
| 2022 | $20 million |
| 2023 | $24 million |
| 2024 | $50 million |
| 2025 | $80 million |
| 2026 | $100 million |
As of 2026, KSI’s net worth is estimated at around $100 million, according to Celebrity Net Worth and other reports.
His wealth grew fast in recent years, mostly thanks to Prime Hydration, the drinks brand he co-owns with Logan Paul. Between September 2022 and September 2023, he reportedly earned about $25 million.
His money comes from many sources, including YouTube, music royalties, boxing pay-per-view events, and other business ventures like Lunchly, XIX Vodka, and Sidemen Clothing. Smart investments across brands helped his fortune climb quickly.
Career
KSI began his career in 2009 by posting FIFA gaming videos on YouTube. His funny and energetic style helped him gain millions of subscribers over time.
In 2013, he joined the Sidemen, a group of YouTubers famous for challenges and sketches. He later branched into music and released hits that charted well in the UK.
He also became a boxer, fighting names like Logan Paul and Tommy Fury. Away from the camera, he co-founded Prime Hydration and Misfits Boxing, turning his fame into a business empire. He retired from boxing in January 2026.
Lesser-Known Facts About KSI
| Fun Fact | Detail |
|---|---|
| Ring Nickname | “The Nightmare” |
| Football Club | Arsenal FC supporter |
| Books Written | Author of three published books |
| Music Milestone | Earned a BRIT Billion award |
| Business Range | Owns brands from drinks to clothing |
KSI is more than just a YouTuber. He has written three books, including one titled “KSI: I Am a Bellend,” showing his playful side.
He is a big Arsenal fan and often talks about football. In his gaming days, he even played FIFA with real footballers.
His music career is impressive too, with over a billion streams earning him recognition in the industry. He has also raised millions for charity through big events, proving there is a lot more to him than internet fame.
KSI Social Media
KSI has a massive online presence spread across many platforms. His main YouTube channel has around 17.8 million subscribers, while his music channel has close to 24.9 million.
On Instagram, he shares updates about his projects, music, and daily life with millions of followers. He is also active on X (formerly Twitter), where he often interacts with fans and other creators.
You can find him under the handle @ksi on most platforms. He remains one of the most followed British creators in the world, staying active across YouTube, Instagram, and X.
FAQs
What is KSI real name?
His real name is Olajide Olayinka Williams Olatunji, and he is often called JJ.
How old is KSI?
KSI was born on 19 June 1993, which makes him 33 years old in 2026.
What is KSI’s net worth in 2026?
His net worth is estimated at around $100 million.
Is KSI married?
No, he is not married and keeps his relationships very private.
What is KSI known for?
He is known for YouTube, the Sidemen, music, boxing, and co-founding Prime Hydration.