23. Istanbul
Number of billionaires: 26
Billionaires per capita: 1.85 per 1,000,000 people
With a net worth of over $39 billion distributed among its 26 billionaires, there is little surprise that Istanbul makes the list of 25 richest cities in the world with most billionaires per capita. The richest among the 26 is Murat Ulker, who is also the only billionaire in Istanbul to have earned his vast fortune in the foods industry, and instead of slowing down, is planning to significantly increase the holdings and dealings of his company, and by proxy, increasing his own wealth.