Oldham have completed the signing of McLaughlin from Liverpool on a one-year contract, with the option of a further year. McLaughin, 21, has become Steve Robinson's 16th signing as Latics manager.
The versatile youngster is a full Northern Ireland international and can play either on the wing or at full back.
Robinson told Oldham's official website: “Ryan gives us something we haven't got at the moment which is a bit of pace and energy out wide.
“He is a lad I've known since the age of 12 so he brings a lot of pace, energy and quality. He's had a good grounding at Liverpool so we are looking for Ryan to make a big impact."