The incident took place on Friday in central Delhi's Anand Parbat area, after the 19-year-old boy, who is a neighbour of the girl, took her to his room.
The incident came to light when the girl complained to her relatives following which a case was registered under Section 376 (rape) of Indian Penal Code, police said.
"The accused was arrested on the same day after the complaint was filed," Deputy Commissioner of Police (Central) Parmaditya told IANS.
The accused was sent to 14 days judicial custody after he was produced before the court, a senior police officer said, adding that the girl was sent for counselling.