The victim, who hailed from Motihari in Bihar, reached Nepal's southern Bara district to visit the religious site and was gangraped, according to Deputy Superintendent of Police of the district, Rabindra Regmi.
A gang of local men took her to a nearby lonely area in the premises of the temple and raped her on Tuesday afternoon, the police officer told PTI over phone.
A police team, who had been patrolling in the area, heard the victim's screams for help.
The victim is kept under the protection of women and children service centre of the district police office where she was provided with necessary care, food and clothes, the police said.
More than 6,000 buffaloes and tens of thousands of other animals and birds were sacrificed in the five yearly Gadhimai festival on Friday and Saturday at the end of the month long event in Bara district.
More than 2.5 million visitors from both Nepal and India had visited the festival, known for world's largest animal sacrifices.