Gill Hibberd, assistant director (HR) at Hertfordshire County Council, is leaving to head up HR at neighbouring Buckinghamshire County Council in the autumn.
Hibberd, who has been at Hertfordshire for almost six years, will be the new corporate director for HR and organisational development for Buckinghamshire.
She is looking at establishing the first HR shared services centre in partnership with other county councils.
Hibberd said she would be leading the council's ambitious new programme of change, which includes launching a new customer contact centre, HR transformational work and raising the council's profile.
Buckinghamshire County Council has about 14,000 staff and serves a population of 500,000. It has been rated as 'good' by government performance inspectors for the past three years.