The 21-year old left-side player spent part of last season with Leicester City and will now saddle up with the Latics, delighting manager Roberto Martinez.
"Patrick is a player with enormous potential," said Martinez. "Technically he is very gifted, very comfortable in possession and physically, he uses his intensity to defend very effectively.
"He can play left-back or left wing-back and without a doubt he's got a phenomenal career ahead of him.
"We rate Patrick really highly and his professionalism and his personal attributes will be a huge asset to us this season.