Aswell as Lyon, Roma and Lazio; Olympiakos, Marseille and Pairs Saint Germain showed interest in Melchiot. A host of Premiership clubs also showed interest.
"Sometimes it boils down to just how much effort someone puts in to get you," said Melchiot.
"I was impressed by how hard Wigan pushed. You can see what the ambition is like here."
Melchiot joins Titus Bramble and Sibierski at Wigan, all signing on free transfers.
His new manager Chris Hutchings believes he has pulled of a major coup signing the experienced defender.
"There were some big, big clubs, so it is a bit of a coup. I'm delighted to get him and I'm sure he can't wait to get started.
"We've got to show the ambition we've got at this football club, and that I've got, when you meet players, and that comes across in abundance and they want to sign for me.
"That's the most important thing. Now we have got to make sure we get the best out of them." 