KSI and Logan Paul - who have 37 million subscribers between them - are not professional prizefighters, but are set to star in one of the most-watched boxing matches in history when they step into the right in the Manchester Arena.
YouTuber Jordan Antle, who goes by the name TheFearRaiser, says the fight will be one of the biggest events in internet history.
He told the BBC: "This is a massive event and I would definitely say this is going to be one of the biggest internet events so far in history.
"Seeing two YouTubers who have a large fanbase fighting each other live in front of millions of people in unheard of. It's a very strange combination of two worlds and it's attracting a lot of attention because of how different it is."
Meanwhile, Logan Paul - who attracted controversy earlier this year when he appeared to film an apparent suicide victim in Japan - says he hopes the fight will show a new side to him.
He explained: "I don't think this is the redemption. I think it may mark a part of it, but by no means is this fight a redemption for my mistake that happened in January.
"But I think it is an opportunity to for me to have taken a step back from the internet and focus my efforts elsewhere, and it's an opportunity for me to show the world a new version of Logan Paul, not just silly internet vlog boy."