The 21-year-old’s time at Elland Road comes to an end with a single Leeds appearance to his name.
McCarron’s Leeds bow came off the bench in a 4-1 defeat to Arsenal but was a regular at left-back for the Under-23 side.
He join up with his new teammates at the Bet365 Stadium, where he aims to gain senior minutes for the first time since an early career stint at Carlisle United.
Potters boss Michael O’Neill said of McCarron’s arrival: “Liam is a young man but he has already shown that he can deal with the challenge of first-team football. He’s hungry to learn and progress his career and we are really pleased to have secured his services for at least the next three years.”
McCarron signs a three-year deal for an undisclosed fee.