1. Egypt: The most populous Arabic-speaking country, with a large majority of its population speaking Egyptian Arabic.
2. Saudi Arabia: Home to Mecca and Medina, the holiest cities in Islam, Saudi Arabia's official language is Modern Standard Arabic.
3. Morocco: Located in North Africa, Morocco boasts a rich Arabic dialect known as Moroccan Arabic.
4. Algeria: Located in North Africa, Algerian Arabic is the most spoken language in the country.
5. Lebanon: With a diverse linguistic landscape, Lebanese Arabic is widely spoken throughout the country.
It's important to note that while these countries all have Arabic as an official language, there are significant regional variations and dialects within each country.