The internet sensations have 37 million subscribers between them and will go head-to-head at the Manchester Arena in a six-round bout.
Logan Paul is a former state wrestler who made a name for himself on Vine before switching to YouTube, where he’s had 3.9 billion views.
KSI, whose real name is Olatunji Olajide, began his YouTube career back in 2009 and rose to fame with his FIFA videos.
He has since amassed over 19 million subscribers and boasts 4.4 billion views on the video-sharing platform.
KSI vs Logan Paul start time: What time does the fight start?
Once the undercard fights are settled, the duo are scheduled to do their ring walks at 9pm (approx).
The fight itself is due to start around 9.30pm.
KSI vs Logan Paul LIVE stream: How to watch
The fight will be streamed live on YouTube but unlike most events on the service, it won’t be free for fans to watch.
YouTube are charging punters £7.50 in the UK, or $10 in the United States, to witness the action.
KSI vs Logan Paul: Fighter info
KSI
Age: 25
Height: 1.83m
Weight 84.9kg
Logan Paul
Age: 23
Height: 1.88m
Weight: 86kg
KSI vs Logan Paul: Latest odds
KSI 10/11
Draw 16/1
Logan Paul 10/11
Odds from Sky Bet