Senior Sergeant Anthony Bond, of Dunedin, said a bus was heading from Portobello to Dunedin through Macandrew Bay about 7.45am yesterday morning when the driver went over the bumps.
The bus went over the speed bumps, which caused passengers to be thrown up in the air.
A 13-year-old boy fell at the back of the bus and hit his head on one of the seats.
He was assessed by ambulance staff and transported to Dunedin Hospital.
The two new speed bumps were new but had good signage around them.
Otago Regional Council transport manager Doug Rodgers said it was aware of the incident and "will work with the operator to understand what happened, and how this can be avoided in the future".
"We have reached out to the family and offered our support."
A St John spokeswoman said an ambulance took one patient to Dunedin Hospital in a moderate condition