What is the largest tropical rainforest in the world?

The Amazon rainforest is the largest tropical rainforest in the world. It spreads across the Amazon Basin of South America, with the greatest share—about 60 percent—located in Brazil. Smaller portions extend into Peru, Colombia, Bolivia, Venezuela, Ecuador, Guyana, Suriname and French Guiana.

The forest covers roughly 5.5 million square kilometres, although estimates vary depending on whether researchers measure dense forest, the broader biome or the entire drainage basin. It represents more than half of the remaining tropical rainforest on Earth and is one of the planet’s most biodiverse environments.

The Amazon is not a uniform wall of trees. It includes upland forest, seasonally flooded várzea forest, permanently flooded igapó forest, rivers, wetlands and savanna-like areas. The Amazon River and its tributaries shape the region, carrying enormous volumes of freshwater toward the Atlantic Ocean.

An often-repeated claim calls the Amazon the “lungs of the Earth.” Plants do produce oxygen, but the mature ecosystem also consumes much of it through respiration and decomposition. Its global importance is better described through its biodiversity, carbon storage, rainfall recycling and importance to hundreds of Indigenous peoples.