The 30-year-old has joined the Millers’ League One promotion rivals for an undisclosed fee, understood to be six figures, ending a saga that has gone for most of the month.
Tilt spent the first half of the season back on loan at the DW Stadium after failing to get into boss Paul Warne’s side, but the club recalled him earlier this month after a deal for a permanent move could not be struck.
All three parties were keen for Tilt, who also spent last season on loan at the Latics, to leave the AESSEAL New York Stadium before next week’s transfer deadline and a deal was finally agreed this week.
It is understood that the Millers have recouped the £100,000 they paid for him from Blackpool in 2020.
A club statement read: “The 30-year-old had rejoined the Latics on loan during the summer transfer window but the Millers exercised their option to recall the player in January.
"Having discussed the proposition of Tilt returning to Greater Manchester on a permanent basis, it was clear there was an appetite from all parties to strike a deal, with the two clubs agreeing terms earlier this week, with the paperwork finalised on Tuesday afternoon.”
Tilt played just one game for the club in his two years at the club as injuries, the pandemic’s lockdown and form of other players all restricted his appearances.
The Jamaica international is due to return to the AESSEAL New York Stadium for a league game on February 18.
He could also meet his former club in the Papa John’s Trophy after both sides made it through to the semi-finals.
The Millers moved one game away from a Wembley final after they beat fellow League One side Cambridge 7-6 on penalties.
It had ended 1-1 after 90 minutes as Wes Harding’s first career goal was cancelled out by Paul Digby’s leveller before the break.
Goalkeeper Viktor Johansson was the hero in the shootout, saving Adam May’s effort - the first of 14 penalties that was not converted.
Boss Warne said: “I think we’ll play better, but we won and that’s what football is all about.
“We’re one game from Wembley.
“We had to get some game time into some players and I made nine changes. You can see for the lads who haven’t been in the team that you can train as much as you like and do as much running as you want, but nothing replicates games.”