Impressive on-loan with Ross County last season, Campbell has penned a new deal to 2027.
“I’m delighted to extend my stay,” said Campbell, 20, to EvertonTV.
“I’ve been here for seven years now, so to get a new deal and have the chance to kick on is something I’m really grateful for. I’m really happy I’m staying at Everton.
“Last season at Ross Count was challenging, difficult at times due to the relegation battle, but I’m a better player now because of it.
“I learned a lot of things I needed to while being up there.
"The aim now is just to keep developing as a player. I’m here as an Everton player, I want to kick on here and be involved as a first-team player.
"But if I need to go out on loan and develop my game further, I’m more than happy to do that."