Finland, a Nordic nation of 5.5 million people, ranked as the world's happiest country for the second year running while war-torn South Sudan sank to the least contented in a United Nations report released on Wednesday.
The Finnish people, known for their love of forests, lakes and saunas, took their nation to the top in the list of world's happiest countries.
The study used survey data asking citizens in 156 countries how happy they perceive themselves to be along with measures such as life expectancy, income and social support.
The other Nordic countries, as well as the Netherlands, Switzerland, Canada, New Zealand and Austria also made the top ten.
Released on the International Day of Happiness on March 20, the report warned that world happiness has declined in recent years, driven by a sustained fall in India, which this year ranked in 140th place.
As well as performing well on all the indicators, the most content countries all tended to have very stable societies, with happiness levels changing comparatively little since 2005.
Despite the political turmoil brought by Brexit, Britain rose four places in the rankings to 15th.
The United States, meanwhile, continued its slide of recent years, dropping one spot to 19th place.
"This year's report provides sobering evidence of how addictions are causing considerable unhappiness and depression in the US," said professor Jeffrey Sachs, one of the report's authors.
The unhappiest country was South Sudan, where the UN recently said 60 per cent of people face food insecurity following a bloody civil war which has claimed the lives of an estimated 400,000 people. Other conflict-ridden countries, such as Yemen, Afghanistan and the Central African Republic also featured at the bottom of the table.
(With AFP inputs)