John Tradewell, director of democracy, law and transformation, will take control of the council on a temporary basis when current chief executive Nick Bell leaves in October.
The authority has admitted it will not have a permanent boss in place by the time Mr Bell leaves.
A special committee of councillors will meet to decide what extra pay Mr Tradewell should get once he takes on the additional responsibilities.
Paying tribute to the work Mr Bell has done over the last four years, county council leader Philip Atkins said: "Working closely with me and my cabinet over the last four years, Nick has overseen and driven essential and successful changes at Staffordshire County Council through one of the most challenging periods in local government history.
"Through his commitment to innovation, value for money and delivering results for local people, Staffordshire County Council is now recognised as an excellent local authority.
"I thank Nick for the immense contribution his leadership has made to improving Staffordshire's economy, creating more jobs and prosperity for local people, as well as transforming health and social care and improving the way all partners across Staffordshire work together in the interests of our people."
Mr Bell is moving to education, employment and training experts Prospects Group, to take on the role of Chief Executive. He will remain in post in Staffordshire until the autumn.
Philip added: "Nick has agreed to stay with us until October and during that time it will be business as usual, with our chief executive driving a significant programme of work across the council and our partners.
"We will look to recruit a similarly high calibre replacement, as Chief Executive, as soon as possible, and, if required, make any interim arrangements needed to ensure the county council continues to deliver for Staffordshire people."
Mr Bell said: "The last four years have proved to be the most enjoyable, challenging and exciting of my career to date. Everything that has been achieved is testament to the passion and commitment of the political leadership, the team at the county council and partner colleagues across the county to do very best for residents. I feel very sad to be leaving Staffordshire County Council, but confident that they will continue to lead the way in transforming the public sector and improving residents lives."