Which cities have the largest Spanish speaking population?

It's tough to give a definitive list of cities with the *largest* Spanish-speaking population because it depends on how you define "Spanish-speaking." Do you mean:

* Cities with the most Spanish speakers as a proportion of the population? This would be different than cities with the absolute highest number of speakers.

* Cities where Spanish is the primary language? This excludes places like Miami, where English is the official language, but Spanish is widely spoken.

* Cities that are primarily located in Spanish-speaking countries? This would exclude places like New York City, where Spanish is spoken by a significant portion of the population, but is not the dominant language.

Here are some lists based on different criteria:

By absolute number of Spanish speakers:

* Mexico City, Mexico: With over 20 million inhabitants, a large portion of the population is Spanish-speaking.

* Buenos Aires, Argentina: A major urban center with a population of over 13 million.

* Madrid, Spain: The capital of Spain has a population of over 3.2 million.

* New York City, USA: While not a Spanish-speaking country, NYC has a large Hispanic population, making it a major center for Spanish speakers.

* Santiago, Chile: The capital of Chile boasts a population of over 6.6 million.

By percentage of Spanish speakers:

* Madrid, Spain: Over 99% of the population speaks Spanish.

* Santiago, Chile: Over 99% of the population speaks Spanish.

* Buenos Aires, Argentina: Over 99% of the population speaks Spanish.

* Mexico City, Mexico: Over 99% of the population speaks Spanish.

* Guadalajara, Mexico: Over 99% of the population speaks Spanish.

To get a more precise answer, you need to define your criteria more clearly. Do you want a list of cities with the highest absolute number of Spanish speakers? Or are you looking for cities with the highest percentage of Spanish speakers? Let me know and I can provide a more accurate list.