His contract was only for an initial 12 months, but he told Wigan Today last week he was desperate to stay at the DW.
And chairman Talal Al Hammad says a deal has been done, with an announcement expected soon.
"He is a Wigan player for the next season," tweeted Talal during a Twitter Q&A.
McClean had revealed he would be sitting down shortly with the club hierarchy to discuss his future.
"That's something I will obviously sit down and speak with the chairman and the owners," he said.
"But I absolutely love it here, everybody knows that, and there's no place I'd rather be than he
"Coming back after a tough year last year, for personal reasons, was exactly what I needed.
"To finish the first spell the way we did (in 2015), and to put that right this year, it just feels right.
"The club has looked after me and my family from day one, we absolutely love it here.
"And I haven't got any other plans to go anywhere else."
McClean's first spell with Latics ended in relegation from the Championship in 2015, which led to him joining West Brom.
After three years at the Hawthorns, he spent a similar amount of time at Stoke, before jumping at the chance to 'right a wrong' at Wigan.
"The last time I was here, I was part of the team that got relegated to League One," he added.
"So for me personally to be part of the team that's got this club back into the Championship, it feels like I've righted a wrong.
"After speaking to the manager, and seeing the signings the club had already made, I could see the ambition here.
"And to finish the season as league champions, it's a great feeling."
McClean is shortly expected to be on international duty with Ireland before he can put his feet up for the summer.