Passengers will only be able to use free bus passes after 9:30 in Hampshire after £1.5m of savings were approved.
Some weekend and evening subsidised services will also be reduced to cut spending. Passes could previously be used from 9:00.
Claire Walters, chief executive of Bus Users UK, said some older people need buses to avoid social isolation.
But Sean Woodward, the county council's executive member for transport, said many of the routes were underused.
"When there is only one or two people on the bus, it does make it terribly expensive," he said.
The cuts are part of a £100m saving Hampshire County Council has to make by March 2015.