The French-born forward completed his medical at the Black Country club on Monday morning and has put pen to paper on a two-and-a-half-year contract.
Dicko spent the final six weeks of last season on loan at Molineux, scoring once in four appearances, as Wanderers suffered relegation from the Championship.
More recently, the 21-year-old completed a brief loan spell at Rotherham, scoring six goals in six games including a brace against Wolves in a 3-3 draw over the festive period.
And that has convinced Wanderers head coach Kenny Jackett that Dicko is the man to help their assault on promotion from League One.
"I am very pleased that we have signed Nouha," Jackett told the club's official website. "He brings pace to our frontline which we haven't really had, as well as a good goalscoring record.
"He has played against my teams before both when at Blackpool and obviously for Rotherham this year against Wolves.
"He is a player I have seen a lot of and I think he has the qualities that will bring a good complement to the squad."
Dicko made a total of nine first-team appearances for Wigan and enjoyed two loan spells with Blackpool prior to his stints with Wolves and Rotherham.
He becomes Wolves' third signing of the January transfer window to date after James Henry and Michael Jacobs turned their loan moves into permanent deals.
Wanderers have also been linked with former striker Leon Clarke, who on Monday handed in a formal transfer request at Coventry.