He was taken to the University Hospital of Wales in Cardiff after the accident with a white Skoda Octavia taxi on Barry Road at 22:30 GMT on Tuesday.
South Wales Police has confirmed the boy died from his injuries on Wednesday.
Officers are appealing for witnesses following the incident near to the Llewellyn Street junction.
Family liaison officers are supporting the boy's family.
A 16-year-old boy has died of his injuries after being hit by a taxi in Barry.