Jason Koumas has completed his £5.3m move from West Brom to Wigan.
The 27-year-old Welsh midfielder has agreed terms on a four-year deal.
Wigan manager Chris Hutchings said: “Jason is a touch of class and I am convinced he will add a new dimension to the team.
“There were a number of other Premiership clubs interested in him, which makes me even more delighted he’s chosen to join us.”
“We’ve pushed the boat out to get him but now we turn our attention to other targets,” said Hutchings.
“We’ve done well in the transfer market so far but there’s still room to improve the squad further.”
West Brom chairman Jeremy Peace said: “We have said all along we will only consider selling players like Jason if we receive head-turning offers.”
Koumas is Wigan’s fifth signing of the summer, following the earlier arrrivals of Titus Bramble, Mario Melchiot, Antoine Sibierski and Carlo Nash.