Cassidy will put pen to paper on a two-year contract with Latics, with the option of a third year, on July 1 when his Wolves deal expires.
The 22-year-old, who has had loan spells with Tranmere, Notts County and Southend, told the club’s official website: “I’m delighted to get things finalised as it’s been in the pipeline for quite a while. I’m now looking forward to the opportunity.
“I’ll bring hard work, good football and goals to the team. It’s been a difficult couple of years for me and I want to get some confidence back and enjoy football again.
“The manager is full of enthusiasm and has told me what he expects from me next season. When he spoke to me, I instantly thought I want to play for this manager as he can bring confidence back into my game and then get the best out of me.”
Kelly added: “I’m absolutely delighted to get Jake on board. I’ve watched him numerous times before and he was my number one target.
“Jake is different to what we have got. The supporters know the strikers we have and Jake offers something different.
“He is a finisher, has a very good physical presence and can hold up the play and link with the midfield so we are delighted he has joined.
“The support of chairman Simon Corney and the board in the players I have brought in has been tremendous and me and the staff will continue preparations for the new season.”