The Polish passport gives easy access to 185 countries, the same number as the passports of Malta, Australia and the Czech Republic.
Singapore has the world's most powerful passport, its residents having visa-free access to 193 destinations.
South Korea is the runner-up with access to 190 countries, with Japan close behind, with 189, while Germany, Italy, Luxembourg, Spain and Switzerland share joint fourth place, with visa-free access to 188 countries.
The British passport, which was at the top of the index in 2015, now ranks eighth.
Image: Polish Radio
For the first time since the launch of the Henley Passport Index 20 years ago, the United States has not made it to the top 10, sharing 12th place with Malaysia, with visa-free access to 180 destinations.
Image by cytis from Pixabay, free for use under Pixabay Content License
In 2014, the United States topped the list.
Afghanistan sits at the bottom of the index, with its citizens able to access only 24 countries without requiring a visa in advance.
The Henley Passport Index is updated every three months.
(mk/gs)