Now 18, Davis joined Everton as a 13 year-old from Bury.
After signing his two-year contract, Davis told evertonfc.com: "It's a proud feeling because this is something I've been working for all my life. It's surreal to actually have done it – that phrase 'professional footballer' just sounds better than anything else.
"I'd say I'm a leader, I'm aggressive and I love defending. The aim now is to get as many minutes as I can, and to perform when I get my opportunities to play. I want to perform and fight for my place in the team.
"It's positive because everyone in the team is on a high, which brings the whole team together and brings us closer together as mates. That helps us both on and off the field."
Loney ready to kick on
Meanwhile, Scotland youth international striker Ceiran Loney (above) has also penned pro terms to 2027.
Loney, who joined Everton from Patrick Thistle last summer, said: "I'm buzzing – I think it's a big achievement for me in my football career so far.
"It's something that you dream of when you're young, so it's good to see that the hard work is paying off.
"I think my first season with Everton went well. I've definitely got more to show, and I think we'll see that in the next two years. I'm confident in that."