The Chief Executive of Lincolnshire County Council Tony McArdle will step down after more than 12 years in the role.
The council announced he will hand over his formal Chief Executive responsibilities following a council meeting in February.
He will however continue work on some key projects whilst a new Chief Executive is appointed, before departing in the summer.
Tony said: “It’s been a terrific experience for me throughout the time that I have been here, but the time is right for a change and I want to make that change this year.
“Lincolnshire is a great authority and I am proud of all that’s been achieved working with officers and councillors.
“I will be leaving the council in good shape to meet its ambitions for the future.”
Councillor Martin Hill, Leader of Lincolnshire County Council, said: “Tony joined the council in difficult times, and has been a key part of its transformation which has resulted in Lincolnshire being a high performing, innovative council recognised at a national level.
“I know I speak for many people when I say we have enjoyed working with him and wish him every success for the future.”