The mishap took place in south-west Delhi's Dhaula Kuan at around 2:40 PM, police said, adding that the school van was carrying nine students.
The deceased has been identified as Gauri, an UKG student. The injured girl is Kanika.
Both the victims were rushed to Safdarjung hospital where Gauri was declared brought dead. Doctors said Kanika is out of danger.
Van driver Sanjay has been arrested.