Pierre and Danielle Le Guennec were initially handed the suspended jail terms in 2015 after being convicted of possession of stolen goods over the huge trove of Picasso works, including nine rare Cubist collages and a work from his famous Blue Period.
That verdict was upheld in 2016 by a higher court but then quashed by the final appeals court, which ordered a retrial.
The former electrician, 80, and his wife, 76, were not in court Tuesday when they were found guilty for a third time.
"It is a triumph of truth and marks the end of a cover-up," said Jean-Jacques Neuer, lawyer for Picasso's son Claude Ruiz-Picasso.
He accused Le Guennec of playing the art world equivalent of a drug mule in drug trafficking, alleging that rich art dealers had sought to exploit the couple.
Huge collection
The Le Guennecs have always denied stealing the works.
At his original trial Le Guennec claimed that Picasso had presented him with the artworks towards the end of his life to reward him for his loyal service.
But he later changed his account, telling an appeal court that the works were part of a huge collection that Picasso's widow Jacqueline asked him to conceal after the artist's death in 1973.
Le Guennec said he stored more than a dozen garbage bags of unsigned works which Jacqueline later retrieved, except for one bag which she left him saying: "Keep this, it's for you."
Certificate of authenticity
The affair came to light when Pierre Le Guennec attempted to get the works authenticated by Ruiz-Picasso in 2010.
The artist's heirs promptly filed a complaint against him, triggering an investigation.
Commenting on the latest ruling, Neuer said: "If you have 271 works by Picasso and you want to put them on the international market you need a certificate of authenticity.
"If you see the Picasso estate and tell them these works fell from the sky or you picked them up from the bric-a-brac market, there is little chance anyone will believe you."
