The incident happened near the intersection of Halsey Street and Marcy Avenue in the Bedford-Stuyvesant section.
The force of the impact toppled the bus over onto its side, and the entire collision was caught on surveillance camera.
Police say the 55-year-old taxi driver was not drunk, but they are trying to determine if either driver ran a red light.
Three adults and six children were rushed to Woodhull Hospital, where all the victims were treated for non-life threatening injuries and released.
Several Good Samaritans rushed to the scene after the crash to help.
"It was a big impact," witness Milton Rosa said. "When a cab driver hit a bus like that, it just flipped. It rolled over."
Sources tell Eyewitness News that the students are from a school for non-verbal and autistic children in Bushwick.
"The kids were scared, they were shaken up, nervous, crying," Rosa said. "Most of the kids were already taking their seatbelts off, so I started pulling them out of there."
So far, no charges have been filed in the case.