Salman Khan killed the two blackbucks, a protected species, in the western state of Rajasthan while shooting a film.
Four other actors who starred with him in the movie and were also charged with the offence have been acquitted by the court in Jodhpur.
Khan, 52, could now face between one and six years in jail. He can appeal against the verdict.
One of Bollywood's biggest stars, the actor has appeared in more than 100 films and has a huge fan following across the vast spectrum of Indian society.
This is far from his first brush with the law. In December 2015 Khan was cleared in a 2002 hit-and-run case in which a homeless man died.
The original poaching case against him was filed by the local Bishnoi community, who revere and worship the blackbuck.
This is the fourth case filed against the actor in connection with poaching animals during the filming of the 1998 movie Hum Saath Saath Hain.
He has been acquitted in three of those cases.
In 2006, a trial court convicted the actor in two cases of poaching and sentenced him to five years in prison. The Rajasthan high court suspended the sentence the following year, and eventually acquitted him last year.
The state government has appealed against that order in the Supreme Court.