Egyptian Arabic, locally known as Colloquial Egyptian (Arabic: العامية المصرية, [el.ʕæmˈmejjæ l.mɑsˤˈɾejjɑ]), or simply Masri (also Masry) (مَصرى), is the most widely spoken vernacular Arabic dialect in Egypt. It is part of the Afro-Asiatic language family, and originated in the Nile Delta in Lower Egypt. The ca. 100 million Egyptians speak a continuum of dialects, among which Cairene is the most prominent. It is also understood across most of the Arabic-speaking countries due to broad Egyptian influence in the region, including through Egyptian cinema and Egyptian music. These factors help to make it the most widely spoken and by far the most widely studied variety of Arabic.

While it is primarily a spoken language, the written form is used in novels, plays and poems (vernacular literature), as well as in comics, advertising, some newspapers and transcriptions of popular songs. In most other written media and in radio and television news reporting, literary Arabic is used. Literary Arabic is a standardized language based on the language of the Qur'an, i.e. Classical Arabic. The Egyptian vernacular is almost universally written in the Arabic alphabet for local consumption, although it is commonly transcribed into Latin letters or in the International Phonetic Alphabet in linguistics text and textbooks aimed at teaching non-native learners. The dialect's phonetics, grammatical structure, and vocabulary are influenced by the Coptic language; its rich vocabulary is also influenced by European languages such as French, Italian, Greek, and English.