1. Argentina: Buenos Aires
2. Bolivia: Sucre (official), La Paz (administrative)
3. Chile: Santiago
4. Colombia: Bogotá
5. Costa Rica: San José
6. Cuba: Havana
7. Dominican Republic: Santo Domingo
8. Ecuador: Quito
9. El Salvador: San Salvador
10. Equatorial Guinea: Malabo
11. Guatemala: Guatemala City
12. Honduras: Tegucigalpa
13. Mexico: Mexico City
14. Nicaragua: Managua
15. Panama: Panama City
16. Paraguay: Asunción
17. Peru: Lima
18. Spain: Madrid
19. Uruguay: Montevideo
20. Venezuela: Caracas
Note:
* While Sucre is the official capital of Bolivia, La Paz functions as the seat of government.
* Equatorial Guinea is the only African country where Spanish is an official language.
* Spain, while a European country, is included in this list as Spanish originated there.