North America:
* Mexico
* Cuba
* Dominican Republic
* Puerto Rico (US territory)
Central America:
* Guatemala
* Belize
* Honduras
* El Salvador
* Nicaragua
* Costa Rica
* Panama
South America:
* Argentina
* Bolivia
* Chile
* Colombia
* Ecuador
* Paraguay
* Peru
* Uruguay
* Venezuela
Other:
* Equatorial Guinea (in Africa)
It's important to note that while Spanish is the official language in all of these countries, there are also other languages spoken within them.