KSI

Olajide Olayinka Williams "JJ" Olatunji (born 19 June 1993), known professionally as KSI, is an English influencer, professional boxer, and musician. He is a co-founding member of YouTube group the Sidemen, the CEO of Misfits Boxing, and the co-owner of several businesses, including Prime Hydration and Lunchly.

Born in London and raised in Watford to parents of Yoruba heritage, KSI was privately educated at Berkhamsted School. He registered his main YouTube channel KSI—then known as KSIOlajidebt—in 2009 and built a following through his gaming commentary videos of the FIFA video game series. His content later diversified to include vlogs and comedy-style videos. 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 as Forbes's second-top creator of 2023. As of January 2025, he has over 44 million subscribers and 14 billion video views across his three 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.