Cleanest Countries in the World 2025

Cleanliness doesn’t just look better—it actually leads to a better (and longer) life. Clean water, pure air, efficient handling of waste, and effective sanitation can all significantly improve human health.

For example, countries with high air quality scores reduce their citizens’ chances of being exposed to harmful particles such as fine particulate matter (PM2.5). This reduces the frequency of illnesses associated with air pollution, such as respiratory or cardiovascular disease.

Countries with high pollution levels see high rates of non-communicable diseases which account for 72% of all deaths globally, 16% of which are caused by toxic pollution.

The Environmental Performance Index

Researchers at Yale University and Columbia University collaborated with the World Economic Forum (WEF) to measure the cleanliness and environmental friendliness of 180 countries around the world. To accomplish this task, they created the Environmental Performance Index (EPI).

The Environmental Performance Index measures 40 performance indicators across 11 categories related to three overarching policy objectives: ecosystem vitality, climate change performance, and environmental health. These categories include air quality, water and sanitation, biodiversity and habitat, and sustainability. Once the scores are tabulated, the countries are ranked in order from the cleanest to the dirtiest. This enables countries to easily assess how effective their environmental policies are and how close they are to achieving their environmental goals.

The Top 10 Cleanest Countries:

1. Denmark

With a total EPI score of 77.9, Denmark is the cleanest and most environmentally friendly country, according to the 2022 EPI Results. Denmark stands out for its high scores in several categories, including wastewater treatment (100), marine protected areas (100), and heavy metals (100). It also has some of the world’s most comprehensive and effective policies to reduce greenhouse gas emissions and prevent climate change. Denmark’s focus on sustainability shows in the country’s increasing number of eco-friendly hotels, solar-powered boats, and organic food.

2. United Kingdom

The United Kingdom is the second-cleanest country in the world, receiving an EPI of 77.7. This score is impressive, considering the country’s population of 67.5 million. The UK has perfect scores for drinking water, sanitation, and pollution emissions.

3. Finland

Finland, the second Nordic country on the list, is the third-cleanest. About 42% of Finland’s energy comes from renewable energy resources. Finland ranks third in the world for air quality (93.5) and has achieved perfect 100s for sanitation, drinking water, and heavy metals exposure. The country also prioritizes forest and wildlife conservation.

4. Malta

Malta has made an impressive leap in EPI ranking from spot #23 to #4 between 2020 and 2022. In addition, Malta has increased its overall score by 4.5 points while most other countries on the list lost points, sometimes significantly. For example, Switzerland’s EPI dropped from 81.5 to 65.9 in the same time period. Home to beautiful beaches and rock formations, Malta boasts perfect scores for drinking water and nitrous oxide emissions.

5. Sweden

Sweden’s EPI score is 72.7. The country is one of the most sustainability-focused in the world, known both for its low carbon dioxide emissions and for its use of renewable energy sources. Sweden is also focused upon nature and has increased greenery throughout the country while also preserving thousands of acres of forests. The country boasts a perfect score for marine protected areas and did not lose any grasslands or wetlands—important wildlife habitats—in 2022.

6. Luxembourg

Luxembourg has made significant progress in reducing the negative impacts on its environment despite its rapid population and GDP growth. Luxembourg’s overall score is 72.3, but more impressive are its scores in sanitation (100), drinking water (97.8), and wastewater treatment (98). A relatively small nation with about 648,000 inhabitants, Luxembourg is largely rural with plentiful forests and ample nature parks.

7. Slovenia

Like Malta, Slovenia has also made remarkable progress in EPI ranking between 2020 and 2022, moving from 18th position globally to securing a spot in the top 10. In the past decade, the country has been able to curb pollution from industrial installations, effectively separating the SOx and NOx emissions from its economic growth.

8. Austria

With an EPI of 66.5, Austria is the eighth-cleanest country in the world. Austria has stringent regulations for pesticides and fertilizers and is known to have some of Europe’s strictest standards for air pollution and waste management. The nation boasts a perfect score for drinking water. About two-thirds of Austria is covered in dense forests and meadows.

9. Switzerland

Switzerland is the ninth-cleanest country in the world, with an overall EPI of 65.9 and exceptionally high scores for both drinking water (100) and sanitation (100). Perhaps unsurprisingly, Switzerland is known for its clean water and abundant wildlife.

10. Iceland

With an EPI of 62.8, Iceland has gained spot #10 in EPI ranking in 2022, surpassing Germany by only 0.4 points. Home to breathtaking landscapes, Iceland holds perfect scores for drinking water, sanitation, and species habitat index. Its score of 96 for overall air quality is also quite impressive.