The Tanukh (Arabic: تنوخ, romanized: Tanūkh, sometimes referred to as the Tanukhids (التنوخيون, al-Tanūkhiyyūn), was an Arab tribal group whose history in the Arabian Peninsula and the Fertile Crescent spanned the 2nd century CE to the 17th century. The group began as a confederation of Arab tribes in eastern Arabia in the 2nd century and migrated to Mesopotamia during Parthian rule in the 3rd century. The confederation was led around this time by its king Jadhima, whose rule is attested by a Greek–Nabatean inscription and who plays an epic role in the traditional narratives of the pre-Islamic period. At least part of the Tanukh migrated to Byzantine Syria in the 4th century, where they served as the first Arab foederati (tribal confederates) of the empire. The Tanukh's premier place among the foederati was lost after its rebellion in the 380s, but it remained a zealous Orthodox Christian ally of the Byzantines until the Muslim conquest of Syria in the 630s.

Under early Muslim rule, the tribe largely retained its Christian faith and settlements around Qinnasrin and Aleppo. The Tanukh was an ally of the Syria-based Umayyad Caliphate and became part of the Umayyads' main tribal support base, the Quda'a confederation. The Tanukh's fortunes, like that of Syria in general, declined under the Iraq-based Abbasid Caliphate, which forced its tribesmen to convert to Islam in 780. As a result of attacks during the Fourth Muslim Civil War in the early 9th century, the Tanukh's area of settlement shifted to Ma'arrat al-Nu'man and the coastal mountains between Latakia and Homs, which by the 10th century were called 'Jabal Tanukh'.

Tanukhid tribesmen later settled in the Gharb area outside Beirut in Mount Lebanon and in the 11th century, they became one of the leading tribal groups to embrace the new Druze faith. A Tanukhid family of the Gharb, the Buhturids (commonly called after their parent tribe 'Tanukh'), held the area almost perpetually throughout Crusader, Ayyubid and Mamluk rule and produced one of the major religious thinkers of the Druze, the 15th-century al-Sayyid al-Tanukhi. Their influence gave way to an allied Druze clan in Mount Lebanon, the Ma'ns of the Chouf, but they continued to locally dominate the Gharb well into the Ottoman era in the 16th and 17th centuries. The Buhturids were eliminated by a rival Druze family in the 1630s.

The early Arabic tradition, particularly the works of the Kufan historian Ibn al-Kalbi (d. 819), claim that the Tanukh was a confederation of migrant Arab tribes formed in Bahrayn (eastern Arabia). The traditional narratives describe the constituent tribes' migration from the Tihamah (the western Arabian coastlands of Mecca to Yemen (southern Arabia)) to Bahrayn. While modern historians question or dismiss the historicity of the migration from Tihamah, there is general acceptance that the Tanukh was forged or present in Bahrayn by the 2nd century CE. Ptolemy refers to the Tanukh in eastern Arabia in his Geography, dated c. 150, but they are not mentioned living in the region in Pliny's earlier Natural History, dated 77 CE, confirming its 2nd-century formation there.

From Bahrayn, the Tanukh migrated to central Iraq (the middle Euphrates river valley), perhaps during Parthian rule, i.e. before 220 CE. Their presence in Iraq is supported by a late 3rd-century Sabian inscription mentioning the Himyarite king Shammar Yuharish's dispatch of ambassadors to the capitals of the Sasanian Empire (which succeeded Parthia) and the "land of Tanukh". They may have been assaulted by the Sasanian king Shapur I (r. 240–270) during his capture of Hatra in c. 240. Sometime afterward, Jadhima al-Abrash became king of the Tanukh. Jadhima is an obscure figure who plays an epic role as the folk hero-king of the Tanukh in the traditional narrative, but his existence is attested by a 3rd-century Greek and Nabatean inscription found in Umm al-Jimal (in modern northern Jordan), which mentions "Jadhima" as the "king of Tanukh". According to Retso, Jadhima's influence must have at least spanned the middle Euphrates and possibly the Syrian Desert.

At least a segment of the Tanukh left Mesopotamia sometime after the Sasanian victory at Hatra in the mid-3rd century and established itself in Byzantine Syria. By the 4th century, they became the first Arab tribal group to serve as foederati (confederates) of the Byzantines. The Arabic tradition names Jadhima's nephew as Amr ibn Adi of the Lakhm tribe, which dwelt in southern Syria at that time. It is likely he is the same as the "Amr, king of the Lakhm" mentioned in a Parthian inscription as a vassal of the Sasanian emperor Narseh (r. 293–302). Moreover, Amr's son was likely the "Imru al-Qays, son of Amr, king of the Arabs", whose Arabic epitaph (the Namara inscription in Syria) dates his death to 328 CE. As blood relatives of Imru al-Qays through Jadhima, the Tanukh in Syria may have been affiliated with him.

Shahid suggests that the Tanukh was the tribe of the Arab tribal queen Mavia, whose tribal identity is not known. Mavia went to war with Emperor Valens during the 370s. By then, the Tanukh were ardent Orthodox Christians and Mavia's war with Valens, who embraced Arien theology, was influenced by their doctrinal differences. The Tanukh revolted against the Byzantines in c. 380, during the reign of Emperor Theodosius I, and their rebellion was suppressed by the magister militum Richomer. This marked the end of their role as the principal Arab federates of the Byzantines in Syria, which was held by the Salihids by the 5th century. Little is known of the Tanukh for the remainder of Byzantine rule, but according to Shahid, they remained Christian federates of the empire.

During the Muslim conquest of Syria in the 630s, the Tanukh fought on the Byzantine side. The tribe participated in the battle of Dumat al-Jandal in 634 against the Muslim Arab forces of Khalid ibn al-Walid and in the failed Byzantine counteroffensive against Muslim forces at Homs in 637. They submitted to the Muslim commander Abu Ubayda ibn al-Jarrah when the latter approached their hadir (encampments) at Qinnasrin and Aleppo in 638. Part of the tribe retreated with Byzantine forces into Anatolia and part remained in northern Syria.