Saudi Arabia
The official language of Saudi Arabia is Arabic. The three main regional variants spoken by Saudis are Hejazi Arabic (about 6 million speakers), Najdi Arabic (about 8 million speakers), and Gulf Arabic (about 0.2 million speakers). Saudi Sign Language is the principal language of the deaf community. The large expatriate communities also speak their own languages, the most numerous of which are Tagalog (700,000), Rohingya (400,000), Urdu (380,000), Egyptian Arabic (300,000), and Indonesian (250,000).
Influence of Arabic on other languages
Arabic has had a great influence on other languages, especially in vocabulary. The influence of Arabic has been most profound in those countries dominated by Islam or Islamic power. Arabic is a major source of vocabulary for languages as diverse as Amharic, Baluchi, Bengali, Berber, Bosnian, Chaldean, Chechen, Croatian, Dagestani, English, German, Gujarati, Hausa,
Hebrew, 
Hindi,
Kazakh, Kurdish, Kutchi, Kyrgyz, Malay (Malaysian and Indonesian), Pashto, Persian, Punjabi, Rohingya, Romance languages (French, Catalan, Italian, Portuguese, Sicilian, Spanish, etc.) Saraiki, Sindhi, Somali, Sylheti, Swahili, Tagalog, Tigrinya, Turkish, Turkmen, Urdu, Uyghur, Uzbek, Visayan and Wolof as well as other languages in countries where these languages are spoken. For example, the Arabic word for "book" (كتاب "kitāb") is used in most of the languages listed. Other languages such as Maltese and Nubi derive from Arabic, rather than merely borrowing vocabulary. Spanish has the largest Arabic influenced vocabulary outside the Islamic world due to Muslim rule in the Iberian Peninsula from 711 until 1492 known as Al-Andalus, although Spain's re-christianization and resulting loss of contact with Quranic Arabic has led to a significant shift in both meaning and pronunciation of Spanish words of Arabic etymology.