When Hill returned to the Silverlake Stadium in April this year, the role he accepted was as director of football.
His remit was to bring a period of stability to the club, following a turbulent time, both on and off the pitch.
As a result, Hill also took over the reins as first-team manager, and last season ensured that the club maintained its status in the National League.
He has also worked extremely hard behind the scenes in areas that are vitally important, but often unseen.
Hessenthaler joined the club at the start of the season as assistant-manager and the club are delighted that he has accepted the opportunity to become first-team manager.
He has plenty of managerial experience, having twice been in charge at Gillingham, as well as a period in caretaker charge, as well as with Eastleigh`s league rivals Dover Athletic and Leyton Orient.
Eastleigh`s CEO Mark Jewell told the club`s official website: “Now seems to be a logical time to make the change. Richard brought Hessy to the club at the start of the season. He has a great track record, is well liked and has fitted in extremely well. It goes without saying that we have every confidence in him.
“This will allow Hilly to move, full-time, into his role as director of football. There is a lot to do, both on and off the pitch, and I very much look forward to working with them both, in their new roles”.