Arab Christians (Arabic: العرب المسيحيين‎ Al-'Arab Al-Masihiyin) are ethnic Arabs of the Christian faith, They are descended from ancient Arab Christian clans that did not convert to Islam, such as the Kahlani Qahtani tribes of ancient Yemen (i.e. Ghassanids, and Banu Judham) who settled in Transjordan and Syria, as well as Arabized Christians, such as Melkites and Rum Christians.

First Arab tribes to adopt Christianity were likely Nabateans and Ghassanids. During the 5th and 6th centuries the Ghassanids, who adopted Monophysite Christianity, formed one of the most powerful confederations allied to Christian Byzantium, being a buffer against the pagan tribes of Arabia. The last king of the Lakhmids, Nu'man III, a client of the Sasanian (Persian) Empire in the late sixth century AD, also converted to Christianity (in this case, to the Nestorian sect). Arab Christians played important roles in Al-Nahda, and because Arab Christians formed the educated upper and bourgeois classes, they have had a significant impact in politics, business and culture, and most important figures of the Al-Nahda movement were Christian Arabs. Today Arab Christians play important roles in the Arab world, and Christians are relatively wealthy, well educated, and politically moderate.