The Muslim conquest of the Levant (Arabic: فَتْحُ الشَّام, romanized: Fatḥ al-šām; lit. 'Conquest of Syria'), or Arab conquest of Syria, was a 634–638 CE conquest of Byzantine Syria by the Rashidun Caliphate.

A part of the wider Arab–Byzantine wars, the Levant was brought under Arab Muslim rule and developed into the provincial region of Bilad al-Sham. Clashes between the Arabs and Byzantines on the southern Levantine borders of the Byzantine Empire had occurred during the lifetime of Muhammad, with the Battle of Muʿtah in 629 CE. However, the actual conquest did not begin until 634, two years after Muhammad's death. It was led by the first two Rashidun caliphs who succeeded Muhammad: Abu Bakr and Umar ibn al-Khattab. During this time, Khalid ibn al-Walid was the most important leader of the Rashidun army.

Syria had been under Roman rule for seven centuries prior to the Arab Muslim conquest and had been invaded by the Sassanid Persians on a number of occasions during the 3rd, 6th and 7th centuries; it had also been subject to raids by the Sassanids' Arab allies, the Lakhmids. During the Roman period, beginning after the fall of Jerusalem in the year 70, the entire region (Judea, Samaria, and the Galilee) was renamed Palaestina, subdivided into Diocese I and II. The Romans also renamed an area of land including the Negev, Sinai, and the west coast of the Arabian Peninsula as Palaestina Salutaris, sometimes called Palaestina III or Palaestina Tertia. Part of the area was ruled by the Arab vassal state of the Ghassanids' symmachos.

During the last of the Roman-Persian Wars, beginning in 603, the Persians under Khosrau II had succeeded in occupying Syria, Palestine and Egypt for over a decade before being forced by the victories of Heraclius to conclude the peace of 628. Thus, on the eve of the Muslim conquests the Romans (or Byzantines as modern Western historians conventionally refer to Romans of this period) were still in the process of rebuilding their authority in these territories, which in some areas had been lost to them for almost twenty years. Politically, the Syrian region consisted of two provinces: Syria proper stretched from Antioch and Aleppo in the north to the top of the Dead Sea. To the west and south of the Dead Sea lay the province of Palestine.

Syria was mostly made up of Aramaic and Greek speakers with a partly Arab population, especially in its eastern and southern parts. The Arabs of Syria were people of no consequence until the migration of the powerful Ghassanid tribe from Yemen to Syria, who converted to Christianity and thereafter ruled a semi-autonomous state with their own king under Roman vassalage. The Ghassanid Dynasty became one of the honoured princely dynasties of the Empire, with the Ghassanid king ruling over the Arabs in Jordan and Southern Syria from his capital at Bostra. The last of the Ghassanid kings, who ruled at the time of the Muslim invasion, was Jabalah ibn al-Aiham.

The Byzantine Emperor Heraclius, after re-capturing Syria from the Sassanians, set up new defense lines from Gaza to the south end of the Dead Sea. These lines were only designed to protect communications from bandits, and the bulk of the Byzantine defenses were concentrated in Northern Syria facing the traditional foes, the Sassanid Persians. The drawback of this defense line was that it enabled the Muslims, advancing from the desert in the south, to reach as far north as Gaza before meeting regular Byzantine troops.

The 7th century was a time of rapid military change in the Byzantine Empire. The empire was certainly not in a state of collapse when it faced the new challenge from Arabia after being exhausted by recent Roman–Persian Wars, but utterly failed to tackle the challenge effectively.

Military confrontations with the Byzantine Empire began during the lifetime of Muhammad. The Battle of Mu'tah was fought in September 629 near the village of Mu'tah, east of the Jordan River and Karak in Karak Governorate, between the forces of the Islamic prophet Muhammad and the forces of the Byzantine Empire and their Arab Christian Ghassanid vassals. In Islamic historical sources, the battle is usually described as the Muslims' attempt to take retribution against the Ghassanids after a Ghassanid official executed Muhammad's emissary who was en route to Bosra. During the battle the Muslim army was routed. After three Muslim leaders were killed, the command was given to Khalid ibn al-Walid and he succeeded in saving the rest of the forces. The surviving Muslim forces retreated to Medina.