Dylan Kerr has left his academy coaching role after a accepting an offer to become head coach of Kenyan club Gor Mahia FC.
Kerr, who has held various overseas coaching roles, joined Chesterfield a year ago as lead foundation development phase coach.
Academy manager Mark Smith has thanked Kerr for his input over the last 12 months, adding: "I am sorry to see Dylan go but this is a great opportunity for him and he felt that he could not turn the offer down.
"Dylan leaves with our good wishes and I would like to wish him all the very best for the future."
Applications are now being invited to fill the vacancy created by Kerr's departure.