Trivia: What is the most populous city in the Southern Hemisphere?
Rio de Janeiro, Brazil
Jakarta, Indonesia
São Paulo, Brazil
Sydney, Australia
Correct Answer: São Paulo, Brazil
So why is this answer correct? : São Paulo, Brazil is one of the most populous cities in the world and the most populous city in the Southern Hemisphere. Boasting a population of nearly 22 million people, São Paulo is by far the largest city in South America.