The Ivorian defensive midfielder has joined the club on a five-year contract for a reported fee said to be in the region of £25 million.
Having impressed with French club RC Lens, Gbamin joined Mainz in 2016 as he scored just three times for the Die Nullfünfer in ninety-five appearances.
Putting pen to paper, the new Toffees player expressed how excited he is to join a great club like Everton.
"It’s a big moment with a lot of emotion and now it’s on me to prove on the pitch why they bought me.
I’m excited because Everton is a great club here in England with a big history and ambition so I didn’t think for more than a moment - I wanted to come here.
“I like to go in the duels. I like to run a lot and tackle. I also pass good and have a good transition. All the rest, the fans will see. I will give everything on the pitch."
After Gbamin expressed his delight in joining a Premier League outfit, club manager, Marco Silva also added his voice to the finalised deal.
"Jean-Philippe is a player who has developed really well during the last three seasons and achieved a very good level of performance playing in a high-level competition like the Bundesliga.
“He is ready for this challenge - to come and help us to keep getting better. He is full of ambition to play for Everton, fits with our model and he will give us different solutions in our midfield."
Gbamin becomes Everton's fourth summer signing and are also expected to recruit Moise Kean from Italian Serie A champions Juventus as their fifth signing.
