'Exceptional' former Leeds United, Barnsley and Rotherham United man joins National League side
He was also a Barnsley icon in his playing days, making over 300 appearances for the Reds.
Oldham are currently being led on an interim basis by Steve Thompson, Redfearn’s former assistant during his time in the Leeds dugout.
The roles have now been reversed, with Redfearn arriving at Oldham to assist Thompson in his duties as caretaker manager.
Thompson said: “I’m really pleased to have Neil on board, he’s an exceptional coach and is someone I’ve known and trusted throughout my career.
“I came through the ranks at Bolton with Redders, we were both apprentices and made our debuts together so I’ve known him a long time.
“He is very well-respected already at Oldham and as a coach he is a big asset for both myself and the club.
“We were manager and assistant at Leeds and we’ve always kept in touch. He knows how to get the best out of players and I’m delighted to have him alongside Paul Murray and Steve Collis.”