The former England youth team player moved from Manchester United to join his former mentor Rene Meulensteen at Craven Cottage on the final day of the January transfer window.
Tunnicliffe, 21, made his Premier League debut against his boyhood club in the 2-2 draw at Old Trafford and also retained his place in the Cottagers' midfield in the 3-2 home defeat by Liverpool.
However, new Fulham boss Felix Magath has told the youngster he is surplus to current requirements and allowed him to return north on loan.
The former Peterborough United and Barnsley loanee spent the first half of this season on loan at Ipswich Town, making 29 appearances including one at the DW Stadium as Latics won 2-0 in September.
Latics manager Uwe Rosler said: "Ryan is a very promising prospect player who has experience in the Championship, and after we lost Ben (Watson to broken leg), I am delighted we have got someone who is so football-educated, having come through the ranks at Manchester United under Sir Alex Ferguson.
"He is a different type of player from Ben but will definitely add a new dimension to us."