Which hemisphere does Arabic speaking people live in?

It's not accurate to say Arabic-speaking people live in just one hemisphere. While a large majority of Arabic speakers live in the Northern Hemisphere, there are also significant Arabic-speaking populations in the Southern Hemisphere, primarily in:

* Africa: Countries like Somalia, Djibouti, and parts of South Africa.

* Australia: A small but notable Arabic-speaking community in major cities.

Therefore, it's more accurate to say that Arabic speakers are spread across both hemispheres.