The npower League Two club announced the news on their official website, where Matt was photographed posing with a Fleetwood shirt.
The 22-year-old's move is subject to a medical being completed and he is set to go straight into Graham Alexander's squad to face Bristol Rovers this weekend.
Matt was prevented from playing for nine months due to work permit issues but has returned in style for Harriers with eight goals in as many appearances and recently agreed a new 18-month contract at Aggborough.
Kidderminster chairman Mark Serrell told his club's official website: "We included a clause within Jamille's new agreement that was designed to offer the club a little more security and, in our view, hopefully keep him with us for at least the foreseeable future.
"We had not envisaged at all that any club would meet the criteria of that clause quite so soon but Fleetwood Town have done so - their officials made an approach properly and through the correct channels which we commend.
"Naturally we do not wish to lose Jamille's services but accept that this move is potentially a very fruitful one for him and we wish him well with whatever he decides to do."