The borough council currently empties black bins every week, which is also the case in neighbouring Bournemouth.
The approval of a system for collections every other week aims to save the authority £633,000 a year.
It is also hoped it will encourage more recycling. The changes are due to be implemented in autumn 2016.
The authority said it needed to make savings of between £18m and £20m over the next four years.
Plans to axe weekly household bin collections in Poole have been approved by councillors.