Cereal farmer Paul Francois has been fighting Monsanto, a formerly US company which was bought by Germany's Bayer last year, for the past 12 years.
He denounced what he called years of "legal harassment" by Monsanto, which can still appeal Thursday's ruling by the Cour de Cassation, a top French appeals court.
The ruling, he said, was "a message to the government," which he urged to ban other toxic pesticides that contain glyphosate, used in Monsanto's top-selling Roundup.
Monsanto is facing thousands of US lawsuits over glyphosate exposure, and last month was ordered by a San Francisco court to pay around $80 million to a retiree suffering from non-Hodgkin's lymphoma.
He argued that Monsanto was aware of Lasso's dangers long before it was withdrawn from the French market, and sought damages of more than one million euros ($1.13 million) for chronic neurological damage that required long hospital stays.
It did order the company to pay 50,000 euros immediately for Francois's legal fees.
"The plaintiff's assumed technical knowledge does not excuse the lack of information on the product and its harmful effects—a farmer is not a chemist," it added.
Last month, a San Francisco court ordered the $80 million pay-out to a retiree who blames its popular Roundup weedkiller, which contains glyphosate, for causing his non-Hodgkin's lymphoma.
It had already been ordered last year to pay $78.5 million to a California groundskeeper who attributed his non-Hodgkin's lymphoma to using Roundup as well as Monsanto's Ranger Pro.
Monsanto denies that Roundup causes cancer and has challenged findings by the International Agency for Research on Cancer, an arm of the World Health Organization (WHO), which classified glyphosate as a "probable carcinogen" in 2015.
But Bayer, which paid $63 billion for Monsanto last year, has seen its stock plunge some 40 percent since the takeover was completed last June, largely reflecting fears of Monsanto's exposure to lawsuits.