Sidemen star KSI has a staggering net worth and secret girlfriend as the YouTube group continue to go from strength to strength.

The online group of content creators and influencers shar their YouTube content on their regular Sunday slot and have a huge online following. Having first garnered interest through their gaming content back in 2013, the Sidemen group later ventured into more varied content and have even been involved in a Netflix documentary showcasing their success.

Some members are also known for appearing elsewhere. It was previously reported that JJ, also known by his online alias of KSI, has been confirmed as a full-time judge on the next upcoming series of Britain's Got Talent.

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We have taken a look at the online personality, known as KSI, including his net worth, meaning behind his chosen name and secret girlfriend.

According to celebritynetworth.com, KSI has a staggering net worth of $100million, which roughly equates to a little less than £80million. KSI not only reached fame through his online content, but he also has a musical career and is a boxer.

He also created the sell out drink Prime, alongside Logan Paul, which became highly sought after, becoming a viral phenomenon. So it's no surprise the star is seeing huge financial success.

According to the BBC, KSI, alongside the Sidemen, are amongst the UK's richest gamers.

KSI has had a number of hits and has even been nominated for two Brit Awards, with the latest being in 2025 for his hit Thick Of It for Song Of The Year. He has also entered into huge collaborations with names like Tom Grennan and Anne-Marie.

In 2024, the 32-year-old joined the line up for Hits Radio Live performing to sell out crowds as well as Capital's Summertime Ball in 2025. Some of his songs which fans may recognise include Holiday, Not Over Yet and Summer Is Over.

With his real name as Olajide Olayinka Williams Olatunji, the star has also taken part in high profile boxing matches, including that in 2023 with Tommy Fury. It came following a long running feud with the star.

Despite being in the public eye, KSI maintains a relatively private life. According to reports, the star has a long term partner, who he has never shared with fans.

In a previous podcast, KSI opened up about how they had met on Tinder and she is employed by the NHS, living and working a regular "nine to five". He previously stated she "doesn't want to be famous."

The star keeps his partner out of the spotlight and does not post her on his social media. Speaking in the Now You Know YouTube series he previously said: "She wants to just do her job, nine to five, and just help people. And I just think that's sick.

"It’s not part of the industry that I'm in so we can come back together after we both finish work, and then we can just talk about our lives and chill, and it's just nice. And I can just, I'm able to just relax with her and like, it's not work or it's not hard, it's just super easy."

KSI actually stands for Knowledge, Strength, Integrity. According to reports, KSI said the origin of the name was from his gaming days and being part of a Halo clan.

You can watch The Sidemen on YouTube