The annual survey, carried out by polling institute BVA-Gallup for daily newspaper Le Parisien, spoke to the residents of 51 countries across all five continents to measure levels of optimism and pessimism.
The survey found that wealth has little to do with overall happiness, with the gloomiest people to be found in Europe while the happiest were mostly in Africa and Asia.
The unhappiest countries were in Europe, with France at the top with a negative score of 79.
“We have never seen a score this low in 34 years of doing the study,” said Celine Bracq of BVA-Gallup.
Ireland was the second unhappiest country in the study (-68), followed by Austria (-54), Belgium (-54), Bosnia-Herzegovina (-52), Serbia (-50), Ukraine (-48), Spain (-47) and Germany (-39).
The cheeriest people were in Nigeria (+80), Vietnam (+51), Ghana (+50), Uzbekistan (+45), South Sudan (+45), Tunisia (+33) and Cameroon (+33).
Anthropologist Gilles Boetsch told Le Parisien that the French felt particularly downcast for several reasons.
“Parents know that their children won’t necessarily have a better situation than them,” he said.
He also said the gloominess was stoked by fear that key social benefits are dwindling, like retirement and social security.
Despite the negative assessment of its residents, the attractions of France continue to be a hit with the rest of the world.
Around 79 million people visited the country in 2010, confirming its position as the world's most popular tourist destination.