2020 Megacities

In 2020, the world’s megacities—urban areas with populations exceeding 10 million—were predominantly concentrated in Asia, reflecting rapid urbanization and demographic shifts over recent decades. Tokyo remained the world’s largest megacity, with a population surpassing 37 million, a testament to its post-war economic boom and sustained metropolitan growth. Cities like Delhi, Shanghai, and São Paulo also ranked among the largest, each shaped by distinctive historical trajectories: Delhi’s explosive growth was fueled by rural migration and economic liberalization, while Shanghai’s transformation into a global financial hub followed China’s market reforms. In contrast, cities such as New York and Los Angeles, whose populations stabilized or grew more slowly, reflect earlier waves of urbanization and suburbanization in the 20th century. While some megacities, particularly in Africa and South Asia (like Lagos and Dhaka), experienced double-digit growth rates due to high birth rates and rural-to-urban migration, others in developed regions saw slower growth or even population decline, highlighting the diverse challenges and opportunities facing the world’s largest urban centers in 2020.

Data from UN World Urbanization Prospects