The accident occurred shortly after 2:00 p.m. Monday along the 1700 block of Kresson Road.
The student was leaving the school parking lot in her Honda Civic, and when she attempted to make a left onto Kresson the driver's side of her vehicle was struck by the dump trailer.
Police say the truck, loaded with gravel, was traveling eastbound on Kresson and was unable to stop in time.
The 18-year-old Cherry Hill East student was taken to Cooper University Hospital with head trauma and was listed in serious condition.
The student has not yet been identified.
Authorities say no charges are expected to be filed against the dump truck driver.