The exact amount of the deal has not been disclosed, but Mullins will now be a part of the Wycombe team.
Wycombe's head coach, Mike Dodds, expressed his excitement about Mullins' potential and the opportunity to help him grow as a player.
Dodds believes Mullins will be a valuable addition to the team and contribute to the midfield.
Mullins joined Brighton from Bohemians in 2023 and has been a regular member of the U21 team.
Before joining Wycombe, Mullins featured in a senior friendly match for Brighton on Saturday.