Jim Yong Kim said instituting a system that ensures the whole population has access to medical care is key to reducing poverty in the developing world.
"Japan committed to universal health coverage (in 1961) at a time when the GDP per capita wasn't among the highest in the world and at a time when many people outside of Japan thought that Japan could not afford to provide universal health coverage," Kim said.
"The World Bank and leading economic development experts think that was one of the keys to Japanese economic development," Kim said.
After devastation and defeat in World War II, Japan rose quickly to become one of the world's leading economies and enjoyed decades of rapid growth.
Under the Japanese public health system, a patient pays up to 30 percent of their medical bills, with the rest made up from a social insurance scheme and general taxation.
Government ministers from developing nations around the world were invited to the one-day conference in Tokyo, hosted jointly by the World Bank and the Japanese government.
The gathering was aimed at spreading the take-up of universal healthcare to developing nations, with the emphasis on how it could boost growth in poorer countries.
Open-access healthcare is "one of the best things you can do to spur immediate and long-term economic growth... and one way of reducing inequality (which can) slow economic growth," Kim told the meeting.
Japan is a major donor to developing countries, and uses its financial muscle to boost its image around the world as well as to establish relationships that pay dividends later as a country's wealth and ability to trade improves.