Peter Gilroy is to leave Kent County Council as its chief executive next May.
Mr Gilroy announced his plans to leave one of the top jobs in local government to staff on Tuesday. In a letter to staff, he said it was the end of an era and that "there was something special about Kent."
He added: "My career started in voluntary work and I will probably go back to that at some point. It has been a tremendous journey and I want to thank the many, many colleagues who have worked with me to transform services for the people of Kent.
Mr Gilroy, who succeeded Mike Pitt in 2005, has led the county council over one of its most successful periods during which it cemented its reputation as one of the country’s best-performing authorities.
But he also attracted his share of negative headlines when his six-figure salary became known and the council introduced its controversial £1.4m internet TV station, Kent TV.
His departure comes after a career in local government that has spanned more than 30 years and began when he joined Devon county council as a social worker in 1976.
Mr Gilroy joined KCC as a senior assistant social services director from East Sussex in 1991 and led the social services directorate for eight years until being appointed chief executive in 2005.
During his time as social services director, Kent was in the frontline as the UK dealt with the challenge of dealing with a major influx of asylum seekers, an issue that brought the county national attention.
As chief executive he was also instrumental in the authority’s efforts to pioneer new ways of delivering social care, introducing "Telehealth" technology that allowed people to remain in their homes.
Married with two daughters, he lives in The Weald and lists his interests as Native American history, horse-riding and music.