The Oaks Primary School Under-11s team represented Crawley Town in the Southern Kinder Cup.
A total of 11 other school teams representing league one clubs competed in Wiltshire.
The Oaks Primary will face a school representing Oldham Athletic at Wembley Stadium national final on May 24 before the league one play-off final.
Notts County were the first opponents – Oaks 3-1 victory.
The Oaks, who are based in Tilgate, faced Yeovil Town in game two - 3-1 win for Crawley.
Leyton Orient played the third game. A late goal secured a 2-1 win for Crawley.
Colchester United were the fourth opponents - 2-1 Crawley victory.
Swindon played The Oaks in their fifth match. A 4-0 win. The Oaks progressed to the final.
The final between Crawley and Gillingham ended 0-0 after full-time. With seconds remaining in extra-time Josh Hallard scored.
The boys were jubilant and celebrated with teacher Mr Nigel Lake. The Oaks Primary will face a school representing Oldham Athletic at Wembley Stadium national final on May 24 before the league one play-off final.
Oaks squad: Jayden Bow, Callum Chesworth, Oli Cooper, Archie Fuller, Josh Hallard, Harry McKnight, Alessio Pagnani, Will Sharpe