Wigan have signed Gabriel Obertan on a free, plus Rangers goalkeeper Matt Gilks, Eastleigh striker Mikael Mandron and Hartlepool midfielder Josh Laurent for undisclosed fees.
Hull City defender Alex Bruce, 32, and midfielder James Weir, 21, have joined on loan until the end of the season.
Obertan, 27, has signed a contract until the end of the season.
Gilks, 34, has signed an 18-month deal, while Mandron, 22, and Laurent, 21, have agreed two-and-a-half-year deals.
Meanwhile, midfielder Jordi Gomez has joined Rayo Vallecano on a free transfer.
Gomez, 31, returned to the Latics at the start of the season, following their promotion back to the Championship, after his release by Sunderland.