The annual World Happiness Report, that ranks 156 countries' happiness has crowned Finland number one, with the UK languishing in 19th place - again.
Europe's Nordic nations have dominated the index since it was first produced in 2012. By reaching first place, Finland has knocked close neighbour Norway off the top spot.
Britain, one of the world's wealthiest countries, was ranked 18th when the index was first produced in 2012, and it hasn't gone above that position since.
The top ten, after Norway and Finland, is as follows; Denmark, Iceland, Switzerland, the Netherlands, Canada, New Zealand, Sweden and Australia. The United States fell to 18th place from 14th last year.
Meik Wiking, CEO of the Copenhagen-based Happiness Research Institute, said the five Nordic countries that reliably rank high in the index "are doing something right in terms of creating good conditions for good lives".
He said the index showed that personal freedom and social security outweigh residents having to pay "some of the highest taxes in the world".
"Briefly put, (Nordic countries) are good at converting wealth into well-being," Mr Wiking said.
Unlike past years, the annual report published by the UN Sustainable Development Solutions Network also evaluated 117 countries by the happiness and well-being of their immigrants.
Interestingly, surveying immigrants has shown that happiness in "contagious"
"The most striking finding of the report is the remarkable consistency between the happiness of immigrants and the locally born," said John Helliwell, a co-editor of the World Happiness Report.
He added: "Those who move to happier countries gain, while those who move to less happy countries lose."
At the other end of the scale, the two losers of 2017 have swapped place, with Burundi leapfrogging Central African Republic as the World's least happy nation.
Although not detailed in the report, the fact Britain has not got any happier since 2012 is probably down years of austerity and terrible weather.
The top ten happiest nations:
- New Zealand
Top ten least happy nations
- South Sudan
- Central African Republic