Six of the girls were "seriously" injured, mainly with broken bones, police said. The crash, involving a yellow Peugeot car, happened at about 15:20 GMT on Friday near Belvedere Academy.
The driver, a woman in her 80s, was not injured and is helping police with their inquiries.
Officers are appealing for witnesses.
Pupils at the independent girls' secondary school for 11 to 19-year-olds had just finished for the half-term break when the crash happened as buses arrived to collect them.
A passer-by witnessed the collision on Belvidere Road and reported that the vehicle mounted a kerb and struck a number of children.
Seven of the girls, aged between 11 and 13, were taken to Alder Hey children's hospital by ambulance.
A 16-year-old with minor injuries was taken to The Royal Liverpool University Hospital.
One 13-year-old suffered a fractured hip and another girl, also 13, sustained two broken arms. An 11-year-old suffered a head injury.
Supt Mark Wiggins, of Merseyside Police, said officers from the force's specialist roads policing team were continuing their investigation.
"Eight people were injured during the collision, thankfully none critical or life threatening. We are working with the Highways Agency, witnesses, the injured girls and the driver, to piece together exactly how this collision happened," he said.
All roads in the area reopened shortly before 19:00 on Friday.
Anyone with information is asked to contact the roads policing department on 0151 777 5747.
Specialist road investigators remain at the scene of a crash near a Liverpool school in which eight girls, aged between 11 and 16, were hurt.