The majority of councillors at Dorset County Council have voted in favour of pushing ahead with a unitary council.
The council will now explore two options of cutting the number of councils from nine to two in Dorset.
The first option is one unitary council for the county and one for Bournemouth and Poole, while the other would see a unitary council set up for for East Dorset, North Dorset, Purbeck, West Dorset and Weymouth and Portland and one for Bournemouth, Poole and Christchurch.
Cllr Robert Gould, leader of Dorset County Council, said: 'We now have a clear consensus around having one, new council serving the whole "shire" Dorset area, with an enhanced role for town and parish councils to deliver local services and strengthen their identity.
'This would simplify the structure of local government for residents, save money and help our case for a really ambitious devolution deal for Dorset.'
The council will now develop a business case for both options, with a public consultation being held in the summer.