Singapore took the top spot after Paraguay lifted restrictions for Singaporeans.
That means the approximately 3.4million holders of Singaporean passports can now travel to 159 countries either without a visa at all, or can have one issued on arrival.
Germany came in second place, with its citizens able to visit 158 countries without a visa, while Sweden and South Korea tied for third.
The US passport was in sixth place, alongside Malaysia, Ireland and Canada.
Latvia shares tenth place with Lithuania, Poland, Slovakia and Slovenia. Holders of these countries’ passports can travel without a visa to 149 countries. Estonia has ranked 11th with 148 countries.
Afghanistan came bottom of the list with visa-free access to just 22 countries.
Passport Index said the US passport's usefulness has fallen since President Donald Trump took office, with Turkey and the Central African Republic becoming the most recent countries to revoke their visa-free entry for holders.
