The girl was missing since last evening and her body was today recovered from an isolated area, police said.
The accused, Kamlesh Raigar, aged about 30 years, lured the girl with sweets and after taking her to his room raped her, Deputy Commissioner of Police (West) Kailash Chand Bishnoi said.
After the act he strangulated her and dumped the body in a plot, he said.
He was arrested after initial probe indicated his involvement in the matter, the DCP added.