Tausūg (Bahasa Sūg, بَهَسَ سُوْغْ, Filipino: Bahása Sug, Malay: Bahasa Suluk, بهاس سولوق, lit. 'Language of Sulu/the Tausūg people') is an Austronesian language spoken in the province of Sulu in the Philippines and in the eastern area of the state of Sabah, Malaysia. It is widely spoken in the Sulu Archipelago (Sulu, Tawi-Tawi, and Basilan), the Zamboanga Peninsula (Zamboanga del Norte, Zamboanga Sibugay, Zamboanga del Sur, and Zamboanga City), southern Palawan, Malaysia (eastern Sabah), and Indonesia (Tarakan City and Nunukan Regency, province of North Kalimantan).
Tausūg has some lexical similarities or near similarities with Surigaonon language of the provinces Surigao del Norte, Surigao del Sur, and Agusan del Sur and with the Butuanon language of Agusan del Norte; it has also some vocabulary similarities with Sugbuanon, Bicolano, and with other Philippine languages. Many Malay and Arabic words are found in Tausug language.