Among the stations set to close by 2017 are Kidlington and Woodfarm in Oxfordshire.
Reading station will be replaced within the next four years. The force could not guarantee if a new town centre station would open 24 hours a day.
Neighbourhood offices will be opened in some areas, including five in Milton Keynes and four in Aylesbury.
Thames Valley Police intends to save £2.1m a year in operating costs, which it says is the equivalent of 45 police constable roles.
Deputy chief constable Francis Habgood wants officers and the public to see the police's new offices as "out on the street".
He said: "We're trying to provide services so that our police officers and staff can do most of their work out on the streets.
"As an organisation, we have quite a considerable estate and cover a wide geographical area.
"It's important we have a good footprint across the Thames Valley, but some of our estate is elderly and not very efficient.
"We're making sure we have a plan for the future which actually cuts down cost."
Thames Valley police and crime commissioner Anthony Stansfeld said: "We have got to make our offices more efficient as most of them were put in place before mobile technology.
"Our estate needs to be modernised right across the board."
A considerable number of neighbourhood offices will be replaced under the plans. The former station in Wantage, Oxfordshire has already been relocated to a "front counter" facility at the town's library.
Thames Valley Police hopes to raise £22m from the sale of police stations and offices.