The 19-year-old brings plenty of skill with him and is a highly sought-after prospect.
Here are all the details you need to know.
Olise has signed a five-year contract, securing his service to the club until summer 2026.
Following in the footsteps of Yohan Cabaye and Darren Ambrose, we have a new No.7. You can order the newly-released 21/22 away shirt here – including Olise’s name and number.
How to win Olise's signed arrival shirt
Easy: simply join as a 21/22 Member by 23:59 on Wednesday, 14th July, by clicking here! Existing Member? We've already entered you into the competition - just one of many Member benefits.