The 24-year-old moves to Dale for an undisclosed fee from Blackpool, signing a deal until the summer of 2020.
The versatile right-back, who is comfortable playing a number of positions, started his career at Glenavon before joining Liverpool at 16-years-old. After spending three years at the Premier League side, he moved on to Oldham Athletic in 2016, where he made over 60 appearances in two seasons. He left the Latics in the summer to join the Seasiders after opting to stay in League One.
A Northern Ireland international, Belfast born McLaughlin has represented his country at various youth levels and has been capped on five occasions by the senior side.
“I’m really excited and delighted to be here,” said McLaughlin.
“I’ve played against Rochdale over the last two or three years so I know the brand of football that the team plays and I think it suits me.
“I’ve played League One football for the last few seasons so I know what the league is about. I know I can do well for the team – it’s just about proving that.