The 16-year-old arrives from the Saddlers on a scholarship and will go into the Category One youth set-up at Staplewood, where he will continue his development under the expert guidance of Saints' Academy coaching staff.
Pearce's reputation has blossomed with the West Midlands club, starring regularly for the Under-18s team, scoring for the Under-23s and making the bench for the first-team during last season's Leasing.com Trophy campaign – all at the age of just 15.
Pearce said: “It means a lot. Most kids dream of getting to this point in their career and coming to a Category One club with facilities like this.
“A couple of years ago if you would have told me I'd be here I wouldn't have believed you, but you can achieve anything with hard work. I knuckled down and here I am. It's a dream and an honour to be here. I feel I will fit in well here."