Jasmine Allsop, 14, died at the scene in Ann's Hill Road in Gosport, while Olivia Lewry, 16, was taken to hospital but also died, Hampshire Police said.
Detectives launched a murder investigation and a 20-year-old man has been arrested on suspicion of murder. The man is in custody, police said. The girls were pedestrians and were involved in a collision with a green Honda Civic car at about 4am yesterday.
Detective Superintendent Dick Pearson said: "This is an extremely tragic incident which has resulted in the death of two young girls.
"I currently have a team of detectives and other officers, including road collision investigators, working to fully investigate the circumstances."