Sidemen star KSI boasts an impressive net worth and a secret girlfriend as the YouTube group continues to soar in popularity.

The online collective of content creators and influencers share their YouTube content on their regular Sunday slot, amassing a massive online following.

Initially gaining traction through their gaming content back in 2013, the Sidemen later diversified into a variety of content and even featured in a Netflix documentary highlighting their success.

Some members have also made appearances elsewhere. It was previously reported that JJ, better known by his online alias KSI, has been confirmed as a full-time judge on the forthcoming series of Britain's Got Talent.

We've delved into the online personality known as KSI, including his net worth, the meaning behind his chosen name, and his secret girlfriend, reports the Mirror.

According to celebritynetworth.com, KSI has an astounding net worth of $100million, which is roughly just under £80million. KSI achieved fame not only through his online content but also through his music career and boxing.

He also launched the sell-out drink Prime, alongside Logan Paul, which quickly became a viral sensation. So it's no surprise that the star is enjoying significant financial success.

According to the BBC, KSI, along with the Sidemen, are among the UK's wealthiest gamers.

KSI has achieved numerous chart successes and has even secured two Brit Award nominations, with the most recent being in 2025 for his track Thick Of It in the Song Of The Year category. He has also embarked on major collaborations with artists such as Tom Grennan and Anne-Marie.

In 2024, the 32 year old joined the lineup for Hits Radio Live, performing to packed audiences, as well as Capital's Summertime Ball in 2025. Some of his tracks which supporters may recognise include Holiday, Not Over Yet and Summer Is Over.

Born Olajide Olayinka Williams Olatunji, the celebrity has also participated in high-profile boxing bouts, including his 2023 clash with Tommy Fury. This followed an extended rivalry between the pair.

Despite his public profile, KSI keeps a relatively low-key personal life. According to sources, the star has a long-term girlfriend, whom he has never revealed to supporters.

During a previous podcast appearance, KSI revealed how they had connected on Tinder and she works for the NHS, maintaining a standard "nine to five" lifestyle. He previously mentioned she "doesn't want to be famous."

The celebrity shields his girlfriend from public attention and avoids featuring her on his social media platforms. Speaking on the Now You Know YouTube series he previously commented: "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 stands for Knowledge, Strength, Integrity. Reportedly, KSI revealed that the name originated from his gaming days as part of a Halo clan.

You can watch the Sidemen content on YouTube.