11. Karachi, Pakistan
Current population: 16,840,000 people
One-fifth of Pakistan’s urban population resides in Pakistan’s once-capital ‘megacity,’ according to a report by the World Bank. While the number of its residents has soared – up 2.3 per cent since 2021 – its quality of life has been plummeting, with violent crime, inequality and financial instability all contributing to developmental challenges. Karachi is also one of the world’s densest cities; it has 24,000 people living per square kilometre.
10. Osaka, Japan
Current population: 19,060,000 people
The number of people living in Japan’s food-centric and third-largest metropolitan area is actually decreasing – it’s dropped by 0.27 per cent since 2021. But nearly 20,000 humans squeezed into the broader Kansai region (which includes the city of Osaka) of 27,000 kilometres makes for some tight living quarters. And in fact, 7 per cent of Japan’s total population lives within an even smaller space in this region, in the city of Osaka proper and its 42 municipalities.
9. Mumbai, India
Current population: 20,961,000 people
India’s second-largest metropolitan area has its largest in-city population, with over 13 million at last official census count in 2011. Its trains alone carry 6 million people a day, a figure that puts almost every other busy city to shame. Mumbai’s population has surged in the past 20 years – and has in fact doubled since 1991 – as migrants from rural areas move to town looking for work. The practical realities of this flux are grim: reports World Population Review, 41 per cent of residents in Mumbai and its surrounding regions live in slums. If you’re looking for a silver lining, Mumbai may still be growing, but the rate is slowing.