"European and North American countries dominate the top of the list as a result of their histories of progressive social policies," HelpAge said in a press release. Canada and the U.S. rank fifth and eighth, respectively. New Zealand and European countries Germany, the Netherlands, Switzerland and Iceland round out the top nine, with Japan taking the tenth spot.
The report cites U.N. data showing people over the age of 60 have outnumbered the number of children under the age of five since 2000, with older people on track to outnumber children under 15 by 2050.
(Slideshow: The world's richest aging populations)
While the bottom of the list is populated with some of the world's poorest countries, such as Afghanistan, Rwanda and Nigeria, the report notes "money isn't everything."
The five major emerging economies, Brazil, Russia, India, China and South Africa, collectively referred to as the BRICS, don't show a strong correlation between economic growth and older people's wellbeing, it said.
While Brazil and China, ranked 31st and 35th respectively, have made progress in reducing overall poverty and creating some income security for older people, the aged still have higher rates of poverty compared with other age groups, the report said.
Other BRICS don't fare nearly as well, with healthcare in India and Russia, ranked 73rd and 78th respectively, a particular problem, with lower life expectancies.
South Africa ranks at 65th, with income security coming from employer-based retirement plans.
"Older people do not necessarily prosper in fast-growing economies, unless resources are targeted at them," the report said.
(Read More: Retirement homes are no longer taboo in Asia)
Some of the poorest countries based on gross domestic product per capita still manage to rank relatively highly. For example, Sri Lanka, ranked 36th, has seen benefits from long-term investments in education and health care, while Boliva, one of the poorest countries, ranked 46th due to its progressive policy environment with noncontributory pensions and free healthcare for older people.
Indeed, Nepal has managed to outrank Russia, coming in at 77th, after the Asian country introduced a basic pension for people over the age of 70 without other pension income.
"Though limited in value and eligibility and with uneven coverage, this is an example of how a low-income country has chosen to make a start in addressing the old-age poverty challenge," the report said.
— By CNBC.com's Leslie Shaffer. Follow her on Twitter @LeslieShaffer1