Dorjee, who has been missing since early June when he was on a "peace march to Tibet" from McLeod Ganj, was announced the winner at a function here last evening.
His mother, Dombu Kyi, received the award during the opening ceremony of the film festival.
The awards committee head, Lobsang Wangyal, said, "The Free Spirit Award was started in 2003 to honour artistes and individuals for their support to the cause of Tibetan people in particular and world peace, social and environmental issues in general.