According to the report, which scores the passports on the total number of destinations that the holder can access visa-free, Vietnamese passports enable visa-free travel to 55 destinations globally.
In Southeast Asia, the Vietnamese passport is more powerful than Laos (87th) and Myanmar (89th).
Singapore has replaced Japan as the country with the most powerful passport, as the city-state's citizens enjoy visa-free entry to 192 global destinations.
The Malaysian passport was the 11th most powerful in the world, with visa-free access to 180 destinations, while the Thai passport ranked 64th, with its citizens allowed to visit 79 countries without applying for a visa.
The index ranks 199 global passports based on the number of destinations their holders can access without a prior visa. The index is updated in real-time throughout the year, as and when visa policy changes take effect.
In the latest ranking, Japan dropped to third, with visa-free access to 189 destinations around the world. It shares its position with Austria, Finland, France, Luxembourg, the Republic of Korea and Sweden.
Italy, Germany and Spain are joint-second with visa-free access to 190 destinations.
At the bottom of the list is Afghanistan with easy access to 27 destinations. Yemen (99), Pakistan (100), Syria (101) and Iraq (102) round up the bottom five.
Vietnam now allows visa waivers for 25 countries and offers e-visas to citizens of 80 countries and territories.
Although the US passport is still in the top 10 most "powerful" passports in the world (8th place), this country has had the least increase in the passport index over the past 10 years.
The UK, after a decline due to leaving the European Union (EU), has returned to fourth place - the position it held in 2017.
With historical data spanning 18 years, the Henley Passport Index is based on exclusive data from the International Air Transport Association.
The Henley Passport Index is updated quarterly and is considered a standard reference tool when assessing where a passport ranks in terms of global mobility.
