Holders of Singapore's passport enjoy visa-free access to 195 out of 227 destinations, according to the index released in October by London-based global citizenship and residence advisory firm Henley & Partners.
Japan, France, Germany, Italy, and Spain share second place, with visa-free access to 192 destinations worldwide.
In September, Denmark gained visa-free access to China, advancing to third place alongside Austria, Finland, Ireland, Luxembourg, the Netherlands, South Korea, and Sweden, whose citizens can visit 191 destinations without a visa.
British passport holders now enjoy visa-free entry to 190 countries, placing the U.K. in fourth alongside Belgium, New Zealand, Norway, and Switzerland.
In Southeast Asia, Malaysian passport is the second most powerful after Singapore's. Holders of Malaysian passport enjoy visa-free access to 183 destinations.
Argentina and Hong Kong have also gone up one point in the ranking since July.
"The trend towards increased openness continues with more passports gaining access than losing it," Dominic Volek, head of private clients at Henley & Partners, said.
The Henley Passport Index relies on data from the International Air Transport Association.
Updated quarterly, the index is widely used as a standard reference for assessing global mobility by passport strength.