Additional district judge Jimut Bahan Biswas found Sadhan Ghosh and Shaikh Ali Mohammad guilty of the crime and awarded them life term.
The body of the girl of Plassy Hazraponta under Kaliganj Police station was found in a paddy field on February 20 last year.
Following the family's complaint, the police initiated an investigation and arrested the two. The charge sheet was submitted within 56 days.
Sixteen witnesses deposed during hearing of the case.