Tourists Jeremie Bellanger, 25, and Fannie Blancho, 23, went missing in August 2010 while traveling in a village in northern Bolivia, part of a months-long dream holiday in South America.
The couple's bodies have never been found.
Their parents were present when a Bolivian court sentenced Jaime Martinez to 30 years in jail without the possibility of parole for the murders.
Martinez, 31, the son of a wealthy dairy farmer, was convicted of being the ringleader of a group of four that killed the couple after sexually assaulting the woman.
The other three accused, who include Martinez's father, were acquitted by the court in the northern city of Trinidad.
Patrick Bellanger, the father of Jeremie, told AFP by telephone from Trinidad that he was satisfied with the Martinez verdict, but added: "We are not happy with the decision for the other accused and intend to appeal."
Bellanger, who along with other family members fought for more than three years to see justice done, said: "It has been a real nightmare. It was very hard, especially for my wife, my sister and me too.
"It is important to see the culprits punished."