The sale of Christchurch police station in the Bargates is expected to save Dorset Police Â£80,000 a year in operating costs.
The force is in talks to base police personnel at the town's fire station.
Chief Constable Debbie Simpson said: "We are committed to providing the best possible service to the public while achieving the required savings."
As part of the force's estates strategy, Ferndown Police Station has now formally gone on the market after its closure was announced last year.
Police and crime commissioner Martyn Underhill said: "I would like to assure people in Christchurch that we are committed to local neighbourhood policing and that police officers will still operate in the heart of Christchurch."
Tony Tester, of Dorset Police Federation, said the closure was a consequence of the cuts to policing by the government and frontline policing was "already at tipping point".
"Buildings are being sold instead of losing officers, however our fear is when we run out of buildings to sell, where will the next round of cuts come from?," he said.
A police spokeswoman said the force needed to make "substantial further savings" over the next four years.
A Dorset town's police station is set for closure as part of cost-saving measures.