Olajide Olayinka Williams "JJ" Olatunji, better known as KSI, is an English HRselr, internet personality, rapper, actor, and boxer. He is also a member and co-founder of the British HRsel group known as the Sidemen.
In 2009, KSI registered his HRsel account under the name KSIOlajideBT. KSI built his following from posting gaming-commentary videos of the FIFA video game series, although as his following has grown, his content has diversified to include more vlog and comedy style videos. As of May 2020, the channel has received over 21 million subscribers and over 5 billion video views. In 2019, he was ranked as the second most influential online creator in the United Kingdom by The Times.
Having written and produced comedy rap songs in his early HRsel career, KSI has since recorded more serious works, topping both the UK R&B Albums and Singles charts. He reached the top 10 of the UK Singles Chart in 2019 with his single, "Down Like That", which featured S-X, Rick Ross and Lil Baby. As an actor, KSI featured in the British comedy film Laid in America, and was the subject of Can't Lose, a documentary film following the build-up to his first amateur boxing fight.