His contract at Doncaster was ended by mutual consent.
"Once the opportunity arose to return, then I really wanted to grasp that chance," he told the club website.
"Everyone knows what the club means to me and my family, so I was not going to pass up this move.
"I have always kept in touch, so I know I will slot into the squad easily enough and I hope that I can play my part in lifting the club back up to at least League One."
Roberts' arrival at the Racecourse Ground is the latest in a clutch of home-grown talent returning to Wrexham.
Former Dragon Chris Llewellyn re-signed on Friday, while Wrexham-born defenders Ryan Valentine and Steve Evans have also joined.