Global city

The term global city was popularized by sociologist Saskia Sassen in her 1991 book, The Global City: New York, London, Tokyo. Before then, other terms were used for urban centers with roughly the same features. The term 'world city', meaning a city heavily involved in global trade, appeared in a May 1886 description of Liverpool, by The Illustrated London News; British sociologist and geographer Patrick Geddes used the term in 1915. The term 'megacity' entered common use in the late 19th or early 20th century, the earliest known example being a publication by the University of Texas in 1904. In the 21st century, the terms are usually focused on a city's financial power and high technology infrastructure.

Competing groups have devised competing means to classify and rank world cities and to distinguish them from other cities. Although there is a consensus on the leading world cities, the chosen criteria affect which other cities are included. Selection criteria may be based on a yardstick value (e.g., if the producer-service sector is the largest sector then city X is a world city) or on an imminent determination (if the producer-service sector of city X is greater than the combined producer-service sectors of N other cities then city X is a world city.) Although criteria are variable and fluid, typical characteristics of world cities include:

• The most prominent criterion has been providing a variety of international financial services, notably in finance, insurance, real estate, banking, accountancy, and marketing; and their amalgamation of financial headquarters, a stock exchange, and other major financial institutions,
• Headquarters of numerous multinational corporations,
• Domination of the trade and economy of a large surrounding area,
• Major manufacturing centers with port and container facilities,
• Considerable decision-making power daily and at a global level,
• Centers of new ideas and innovation in business, economics, and culture,
• Centers of digital and other media and communications for global networks,
• The dominance of the national region with great international significance,
• The high percentage of residents employed in the services sector and information sector,
• High-quality educational institutions, including renowned universities and research facilities; and attracting international student attendance,
• Multi-functional infrastructure offering some of the best legal, medical, and entertainment facilities in the country,
• High diversity in language, culture, religion, and ideologies.

GaWC World Cities

The Globalization and World Cities Research Network (GaWC) is a British think tank that studies the relationships between world cities in the context of globalization. It is based in the geography department of Loughborough University in Leicestershire, United Kingdom. GaWC was founded by Peter J. Taylor in 1998. Primarily concerned with what it calls the "advanced producer services" of accountancy, advertising, banking/finance, and law, the cities in the top two classifications in the 2024 edition are:

Alpha ++

• London
• New York City

Alpha +

• Beijing
• Dubai
• Hong Kong
• Paris
• Shanghai
• Singapore
• Sydney
• Tokyo

Global Cities Index (Kearney)

In 2008, the American journal Foreign Policy, working with the consulting firm A.T. Kearney and the Chicago Council on Global Affairs, published a ranking of global cities based on consultation with Saskia Sassen, Witold Rybczynski, and others. The ranking is based on 27 metrics across five dimensions: business activity, human capital, information exchange, cultural experience, and political engagement. The top ranked cities in 2025 are:

1. New York City
2. London
3. Paris
4. Tokyo
5. Singapore
6. Beijing
7. Hong Kong
8. Shanghai
9. Los Angeles
10. Chicago

Global Cities Index (Oxford Economics)

Advisory firm Oxford Economics ranks the world's largest 1,000 cities based on 27 indicators across five categories (economics, human capital, quality of life, environment, and governance) with more weight on economic factors. The top ranked cities in 2025 are:

1. New York City
2. London
3. Paris
4. San Jose
5. Seattle
6. Melbourne
7. Sydney
8. Boston
9. Tokyo
10. San Francisco

Global Power City Index

The Tokyo-based Institute for Urban Strategies at The Mori Memorial Foundation first published a study of global cities in 2008. They are ranked in six categories: economy, research and development, cultural interaction, livability, environment, and accessibility. The top 10 cities in 2025 are:

1. London
2. Tokyo
3. New York City
4. Paris
5. Singapore
6. Seoul
7. Amsterdam
8. Shanghai
9. Dubai
10. Berlin

World's Best Cities ranking

Consultancy firm Resonance publishes the World's Best Cities ranking. They are ranked in three categories: livability, lovability and prosperity, each of them using different factors. The top 10 cities in 2026 are:

1. London
2. New York City
3. Paris
4. Tokyo
5. Madrid
6. Singapore
7. Rome
8. Dubai
9. Berlin
10. Barcelona

Global Financial Centres Index

The Global Financial Centres Index (GFCI) ranks the competitiveness of financial centres based on over 29,000 assessments from an online questionnaire and over 100 indices from organisations such as the World Bank, the Organisation for Economic Co-operation and Development (OECD), and the Economist Intelligence Unit. It was first published in March 2007. It has been jointly published twice per year by the London-based think tank Z/Yen and the China Development Institute since 2015. It is widely quoted as a top source for ranking financial centres.

The 2026 ranking was:

1. New York City
2. London
3. Hong Kong
4. Singapore
5. Shanghai
6. Tokyo
7. Seoul
8. Shenzhen
9. Dubai
10. Zurich