Syria (Arabic: ٱلشَّام, romanized: Ash-Shām or Shaam), also known as Greater Syria or Syria-Palestine, is a historical region located east of the Mediterranean Sea in West Asia, broadly synonymous with the Levant. Throughout history, the term Syria-Palestine referred to the area between the Taurus Mountains in the north and Arabia-Sinai in the south, however in modern times the term "Syria" is used to refer solely to the Syrian Arab Republic.

The term is originally derived from Assyria, an ancient Semitic-speaking civilization centered in northern Mesopotamia, modern-day Iraq. During the Hellenistic period, the term Syria was applied to the entire Levant as Coele-Syria. Under Roman rule, the term was used to refer to the province of Syria, later divided into Syria Phoenicia and Coele Syria, and to the province of Syria Palaestina. Under the Byzantines, the provinces of Syria Prima and Syria Secunda emerged out of Coele Syria. After the Muslim conquest of the Levant, the term was superseded by the Arabic equivalent Shām, and under the Rashidun, Umayyad, Abbasid, and Fatimid caliphates, Bilad al-Sham was the name of the metropolitan province encompassing most of the region. In the 19th century, the name Syria was revived in its modem Arabic form to denote the whole of Bilad al-Sham, either as Suriyah or the modern form Suriyya, which eventually replaced the Arabic name of Bilad al-Sham.

After World War I, the boundaries of the region were last defined in modern times by the proclamation of and subsequent definition by French and British mandatory agreement, as laid out in the Sykes–Picot Agreement. Following the Arab Revolt and Franco-Syrian War, the area was divided and passed to French and British League of Nations mandates. Subsequently, five states — Greater Lebanon, the State of Damascus, the State of Aleppo, the State of Alawites, and the State of Jabal Druze — were established by the French, while the British controlled Mandatory Palestine and the Emirate of Transjordan. The term Syria itself was applied to several mandate states under French rule and the contemporaneous but short-lived Arab Kingdom of Syria. The Syrian-mandate states were gradually unified as the State of Syria and finally became the independent Syrian Republic in 1946. Throughout this period, pan-Syrian nationalists advocated for the creation of a Greater Syria, sometimes as a step toward achieving a broader pan-Arab state.

Several sources indicate that the name Syria itself is derived from Luwian term "Sura/i", and the derivative ancient Greek name: Σύριοι, Sýrioi, or Σύροι, Sýroi, both of which originally derived from Aššūrāyu (Assyria) in northern Mesopotamia, modern-day Iraq and greater Syria For Herodotus in the 5th century BC, Syria extended as far north as the Halys (the modern Kızılırmak River) and as far south as Arabia and Egypt. For Pliny the Elder and Pomponius Mela, Syria covered the entire Fertile Crescent.

In Late Antiquity, "Syria" meant a region located to the east of the Mediterranean Sea, west of the Euphrates River, north of the Arabian Desert and south of the Taurus Mountains, thereby including modern Syria, Lebanon, Jordan, Israel, Palestine, and parts of Southern Turkey, namely the Hatay Province and the western half of the Southeastern Anatolia Region. This late definition is equivalent to the region known in Classical Arabic by the name ash-Shām (Arabic: ٱَلشَّام /ʔaʃ-ʃaːm/, which means the north [country] (from the root šʔm Arabic: شَأْم "left, north")). After the Arab conquest of Byzantine Syria in the 7th century CE, the name Syria fell out of primary use in the region itself, being superseded by the Arabic equivalent Shām, but survived in its original sense in Byzantine and Western European usage, and in Syriac Christian literature. In the 19th century, the name Syria was revived in its modern Arabic form to denote the whole of Bilad al-Sham, either as Suriyah or the modern form Suriyya, which eventually replaced the Arabic name of Bilad al-Sham. After World War I, the name Syria was applied to the French Mandate for Syria and the Lebanon and the contemporaneous but short-lived Arab Kingdom of Syria.

In the most common historical sense, 'Syria' refers to the entire northern Levant, including Alexandretta and the Ancient City of Antioch or in an extended sense the entire Levant as far south as Roman Egypt, including Mesopotamia. The area of "Greater Syria" (Arabic: سُوْرِيَّة ٱلْكُبْرَىٰ, Sūrīyah al-Kubrā); also called "Natural Syria" (Arabic: سُوْرِيَّة ٱلطَّبِيْعِيَّة, Sūrīyah aṭ-Ṭabīʿīyah) or "Northern Land" (Arabic: بِلَاد ٱلشَّام, Bilād ash-Shām), extends roughly over the Bilad al-Sham province of the medieval Arab caliphates, encompassing the Eastern Mediterranean (or Levant) and Western Mesopotamia. The Muslim conquest of the Levant in the seventh century gave rise to this province, which encompassed much of the region of Syria, and came to largely overlap with this concept. Other sources indicate that the term Greater Syria was coined during Ottoman rule, after 1516, to designate the approximate area included in present-day Israel, Palestine, Syria, Jordan, Lebanon.

The uncertainty in the definition of the extent of "Syria" is aggravated by the etymological confusion of the similar-sounding names Syria and Assyria. The question of the etymological identity of the two names remains open today. Regardless of etymology, both were thought of as interchangeable around the time of Herodotus. However, by the time of the Roman Empire, 'Syria' and 'Assyria' began to refer to two separate entities, Roman Syria and Roman Assyria.

Killebrew and Steiner, treating the Levant as the Syrian region, gave the boundaries of the region as such: the Mediterranean Sea to the west, the Arabian Desert to the south, Mesopotamia to the east, and the Taurus Mountains of Anatolia to the north. The Muslim geographer Muhammad al-Idrisi visited the region in 1150 and assigned the northern regions of Bilad al-Sham as the following: