Peninsular Arabic
Peninsular Arabic, or Southern Arabic, are the varieties of Arabic spoken throughout the Arabian Peninsula. This includes the countries of Saudi Arabia, Yemen, Oman, United Arab Emirates, Kuwait, Bahrain, Qatar, Southern Iraq and the tribal people of Jordan (the native Jordanians).
Basic Law of Saudi Arabia
Article 1 states that "God's Book and the Sunna of His Prophet" are the country's constitution and Arabic is the official language with the capital at Riyadh.