Josh Thomas has been with the Swans since he was 12 years old.
The forward, who hails from Bridgend, signed a scholarship in the summer of 2019.
Thomas scored in the previous season's FAW Youth Cup final as Swansea City Under-19s clinched a record-breaking 10th consecutive victory in the competition.
The Wales Under-19 international, who also benefited from one-to-one sessions from Lee Trundle, quickly settled during his first full season in Premier League South; netting seven goals in nine appearances.
His exploits were rewarded with regular opportunities at under-23 level. He played 16 times for the development side in all competitions, scoring on his first start against Middlesbrough.