Dramatic gains in life expectancy have been made globally since 2000, but major inequalities persist within and among countries, the World Health Organisation report said.
Life expectancy increased by five years between 2000 and 2015, the fastest increase since the 1960s, it said.
Those gains reverse declines during the 1990s, when life expectancy fell in Africa because of the AIDS epidemic and in Eastern Europe following the collapse of the Soviet Union.
"The world has made great strides in reducing the needless suffering and premature deaths that arise from preventable and treatable diseases," said Dr Margaret Chan, Director-General of WHO.
Also Read
"But the gains have been uneven. Supporting countries to move towards universal health coverage based on strong primary care is the best thing we can do to make sure no-one is left behind," said Chan.
The report shows that newborns in 29 countries - all of them high-income - have an average life expectancy of 80 years or more, while newborns in 22 others - all of them in sub-Saharan Africa - have life expectancy of less than 60 years.
With an average lifespan of 86.8 years, women in Japan can expect to live the longest. Switzerland enjoys the longest average survival for men, at 81.3 years. People in Sierra Leone have the world's lowest life-expectancy for both sexes: 50.8 years for women and 49.3 years for men.