What are the six biggest spanish speaking countries?

Here are the six biggest Spanish-speaking countries in terms of population:

1. Mexico: 126 million

2. Colombia: 51 million

3. Argentina: 45 million

4. Spain: 47 million

5. Peru: 33 million

6. Venezuela: 28 million

Note: While Spain has a larger population than Argentina, it's important to remember that Spanish is not the only official language in Spain.