The 22-year old defender has signed a three-and-a-half year deal at the Stadium of Light after spending some time on loan with Championship side Sheffield United.
Bardsley has played in the Premier League with Aston Villa before, whilst playing on loan with the Midlanders and Bardsley expressed his delight at completing the £2 million deal.
Bardsley said: "Sunderland have a fantastic manager who has given me the chance to come here and play. I'm delighted, it's a massive club."Black Cats boss Roy Keane said: "We needed to strengthen our defence and Phil is a good addition to the squad."
I feel the signing of Bardsley is a decent one for Sunderland. He is a good right-back that likes to get forward at every oppurtunity and he is certainly not afraid to put a tackle in.