Ms Pinkney, who currently works for Sussex Police, will be the first woman to hold the top position in the Hampshire and Isle of Wight force.
Police and Crime Commissioner Simon Hayes said Ms Pinkney, who takes over from Andy Marsh, was "an incredibly strong candidate".
She will take up her new role on 4 April.
Her appointment was unanimously recommended by the Hampshire Police and Crime Panel following a recruitment process involving 18 partner organisations.
Ms Pinkney said: "I'm absolutely delighted to hear the panel's decision and I look forward to leading the professionals within Hampshire Constabulary and serving the communities across the county and the Isle of Wight."
Mr Hayes said Ms Pinkney, who received the Queen's Police Medal in the 2016 New Year's Honours List, will bring "a wealth of operational experience and strategic leadership" to the role.
Hampshire Constabulary is currently run by acting chief constable Graham McNulty.
Deputy Chief Constable Olivia Pinkney has been confirmed as Hampshire Constabulary's new chief constable.