Danes came out top in the survey that measured health, wealth, education, sense of identity and the aesthetic quality of the landscape.
The survey, published on Friday by a University of Leicester academic, showed seven of the top ten happiest countries were western democracies, with the Bahamas, Bhutan and Brunei being the exceptions.
The United States was 23rd, Germany came in at number 35, and Britain ranked 41st.
Another British study published earlier this month found the tiny South Pacific Ocean archipelago of Vanuatu to be the happiest country on Earth.
That study by the New Economics Foundation, a think-tank, ranked certain members of the Group of Eight industrialised countries much lower than the present survey.
The United States, for example, ranked 150th, Germany 81st and Britain 108th.
"When people are asked if they are happy with their lives, people in countries with good health care, a higher GDP (gross domestic product) per capita, and access to education were much more likely to report being happy," said Adrian White, the social psychologist who carried out the latest study.
The latest Top Ten happy nations are:
"The frustrations of modern life, and the anxieties of the age, seem to be much less significant compared to the health, financial and educational needs in other parts of the world."
White's analysis was based on the findings of more than 100 different studies - by groups like the United Nations and World Health Organisation - questioning 80,000 people around the world.
The Democratic Republic of Congo, Zimbabwe and Burundi were the most unhappy countries in the world.
Countries involved in conflicts, such as Iraq, were not included.