What is inhabitant of southwest Arabia called?

The inhabitants of southwest Arabia are most commonly referred to as Arabs.

Here's a more detailed explanation:

* Southwest Arabia encompasses the modern countries of Yemen and Oman.

* Arab is a broad term that encompasses people from the Arabian Peninsula, including the countries of Saudi Arabia, Yemen, Oman, UAE, Qatar, Bahrain, Kuwait, and parts of Iraq and Jordan.

* While there are various cultural and tribal differences within the Arab world, the term "Arab" is generally accepted to refer to the people of the Arabian Peninsula.

It's important to note that "Arab" is an ethnic and cultural identity, not a specific nationality.