In the Americas:
* Argentina
* Bolivia
* Chile
* Colombia
* Costa Rica
* Cuba
* Dominican Republic
* Ecuador
* El Salvador
* Guatemala
* Honduras
* Mexico
* Nicaragua
* Panama
* Paraguay
* Peru
* Puerto Rico
* Uruguay
* Venezuela
In Europe:
* Spain
* Andorra (Spanish is co-official with Catalan)
* Equatorial Guinea (Spanish is co-official with French and Portuguese)
It's important to note that there are other countries where Spanish is spoken by a significant number of people but it's not an official language, such as the United States.