Levantine Arabic, also called Shami (autonym: شامي, šāmi or اللهجة الشامية, el-lahje š-šāmiyye), is an Arabic variety spoken in the Levant, namely in Syria, Jordan, Lebanon, Palestine, Israel and southern Turkey (historically only in Adana, Mersin and Hatay provinces). With over 60 million speakers, Levantine is, alongside Egyptian, one of the two prestige varieties of spoken Arabic comprehensible all over the Arab world.

Levantine is not officially recognized in any state or territory. Although it is the majority language in Jordan, Lebanon, Palestine, and Syria, it is predominantly used as a spoken vernacular in daily communication, whereas most written and official documents and media in these countries use the official Modern Standard Arabic (MSA), a form of literary Arabic only acquired through formal education that does not function as a native language. In Israel and Turkey, Levantine is a minority language.

The Palestinian dialect is lexically the closest vernacular Arabic variety to MSA, with about 50% of common words. Nevertheless, Levantine and MSA are not mutually intelligible. Levantine speakers therefore often call their language ‏العامية‎ al-ʿāmmiyya listen^ⓘ, 'slang', 'dialect', or 'colloquial'. With the emergence of social media, attitudes toward Levantine have improved. The amount of written Levantine has significantly increased, especially online, where Levantine is written using Arabic, Latin, or Hebrew characters. Levantine pronunciation varies greatly along social, ethnic, and geographical lines. Its grammar is similar to that shared by most vernacular varieties of Arabic. Its lexicon is overwhelmingly Arabic, with a significant Aramaic influence.

The lack of written sources in Levantine makes it impossible to determine its history before the modern period. Aramaic was the dominant language in the Levant starting in the 1st millennium BCE; it coexisted with other languages, including many Arabic dialects spoken by various Arab tribes. With the Muslim conquest of the Levant in the 7th century, new Arabic speakers from the Arabian Peninsula settled in the area, and a lengthy language shift from Aramaic to vernacular Arabic occurred.

Scholars use "Levantine Arabic" to describe the continuum of mutually intelligible dialects spoken across the Levant. Other terms include "Syro-Palestinian", "Eastern Arabic", "East Mediterranean Arabic", "Syro-Lebanese" (as a broad term covering Jordan and Palestine as well), "Greater Syrian", or "Syrian Arabic" (in a broad meaning, referring to all the dialects of Greater Syria, which corresponds to the Levant). Most authors only include sedentary dialects, excluding Levantine Bedawi Arabic of the Syrian Desert and the Negev, which belongs to Peninsular Arabic. Mesopotamian Arabic from northeast Syria is also excluded. Other authors include Bedouin varieties.

The term "Levantine Arabic" is not indigenous and, according to linguists Kristen Brustad and Emilie Zuniga, "it is likely that many speakers would resist the grouping on the basis that the rich phonological, morphological and lexical variation within the Levant carries important social meanings and distinctions." Levantine speakers often call their language ‏العامية‎ al-ʿāmmiyya, 'slang', 'dialect', or 'colloquial' (lit. 'the language of common people'), to contrast it to Modern Standard Arabic (MSA) and Classical Arabic (‏الفصحى‎ al-fuṣḥā, lit. 'the eloquent'). They also call their spoken language ‏عربي‎ ʿarabiyy, 'Arabic'. Alternatively, they identify their language by the name of their country. ‏شامي‎ šāmi can refer to Damascus Arabic, Syrian Arabic, or Levantine as a whole. Lebanese literary figure Said Akl led a movement to recognize the "Lebanese language" as a distinct prestigious language instead of MSA.

Levantine is a variety of Arabic, a Semitic language. There is no consensus regarding the genealogical position of Arabic within the Semitic languages. The position of Levantine and other Arabic vernaculars in the Arabic macrolanguage family has also been contested. According to the Arabic tradition, Classical Arabic was the spoken language of the pre-Islamic and Early Islamic periods and remained stable until today's MSA. According to this view, all Arabic vernaculars, including Levantine, descend from Classical Arabic and were corrupted by contacts with other languages. Several Arabic varieties are closer to other Semitic languages and maintain features not found in Classical Arabic, indicating that these varieties cannot have developed from Classical Arabic. Thus, Arabic vernaculars are not a modified version of the Classical language, which is a sister language rather than their direct ancestor. Classical Arabic and vernacular varieties all developed from an unattested common ancestor, Proto-Arabic. The ISO 639-3 standard classifies Levantine as a language, member of the macrolanguage Arabic.

Sedentary vernaculars (also called dialects) are traditionally classified into five groups according to shared features: Peninsular, Mesopotamian, Levantine, Egyptian, and Maghrebi. The linguistic distance between these vernaculars is at least as large as between Germanic languages or Romance languages. It is, for instance, extremely difficult for Moroccans and Iraqis, each speaking their own variety, to understand each other. Levantine and Egyptian are the two prestige varieties of spoken Arabic; they are also the most widely understood vernaculars in the Arab world and the most commonly taught to non-native speakers outside the Arab world.