KSI

Olajide Olayinka Williams "JJ" Olatunji ( born 19 June 1993), known professionally as KSI, is a British YouTuber, influencer, musician, and former professional boxer. He is a co-founder and former member of YouTube group the Sidemen, the co-founder of Misfits Boxing and co-owner of several businesses, including Prime Hydration and Lunchly. KSI has also served as a judge on Britain's Got Talent since 2025. His main YouTube channel has over 19.2 million subscribers.

Born in London to parents of Yoruba heritage and raised in Watford, KSI was privately educated at Berkhamsted School. He registered the YouTube channel KSIOlajidebt in 2009 and built a following through his commentary videos of the FIFA video game series. His content later diversified to include vlogs and comedic skits. In 2019, he was ranked second by The Sunday Times in its list of most influential online creators in the United Kingdom. In 2021, he was listed in the Europe Entertainment category of Forbes 30 Under 30; he was later ranked by Forbes as the second-top creator of 2023. As of April 2026, he has over 46 million subscribers and 16 billion video views across his four active YouTube channels.

Creating hip-hop music as early as 2011, he first achieved commercial success with "Lamborghini" (featuring P Money) in 2015. His debut EP, Keep Up (2016), topped the UK R&B Albums Chart. He released his debut studio album, Dissimulation, in 2020, which peaked at number two on the UK Albums Chart. His second studio album, All Over the Place (2021), debuted at number one and was certified platinum by the BPI; its lead singles "Don't Play" (with Anne-Marie and Digital Farm Animals) and "Holiday" both debuted at number two on the UK Singles Chart and were nominated for Song of the Year at the Brit Awards. He has achieved fourteen top 40 singles in the United Kingdom, with seven peaking in the top 10. He received the Brit Billion Award in 2024, for amassing over one billion music streams in the United Kingdom. He also starred in the direct-to-video comedy film Laid in America (2016), and has been the subject of multiple documentaries, including Amazon Prime Video's In Real Life (2023).

He was involved in a white-collar boxing match against Joe Weller in February 2018. Two further boxing events against American YouTuber Logan Paul took place, the second of which was a professional bout in which he won via split decision in November 2019. In August 2022, he fought two people in the same night, defeating rapper Swarmz and professional boxer Luis Alcaraz Pineda. In 2023, he fought FaZe Temperrr in January, Joe Fournier in May, and Tommy Fury in October, which he lost via unanimous decision. He retired from boxing in October 2026.