Arabia Felix (lit. 'Fertile/Happy Arabia'; also Ancient Greek: Εὐδαίμων Ἀραβία, romanized: Eudaímōn Arabía) refers to South Arabia, or what is now Yemen, western Saudi Arabia, northern Somalia and eastern Oman.

Arabia Felix was translated into Latin from the Roman translation of the earlier Hellenistic Greek term "Εὐδαίμων Ἀραβία (romanized: Eudaímōn Arabía)", attributed to Eratosthenes of Cyrene. Felix means "fecund, fertile" and "happy, fortunate, blessed", reflecting how of all the regions of Arabian Peninsula, this area received the most amount of irrigation.

Arabia Felix corresponds to present-day Yemen, W. Saudi Arabia, north off Ethiopia, E. Oman and even SW India, and it was one of the three regions into which the Romans divided the peninsula: Arabia Deserta, Arabia Felix, and Arabia Petraea.

The Peninsula's southwestern corner experienced more rainfall in ancient times and was thus much greener than the rest of the peninsula, enjoying more productive fields.

The high peaks and slopes are capable of supporting significant vegetation and river beds called Wadis fertilize the other soils.

It dominated the trade in cinnamon and spices, both its native products and imports from Greater India and the HoA, which contributed to the revenue of Arabia.

Strabo considers Arabia Felix to be composed of five kingdoms, one each of warriors, farmers, "those who engage in the mechanical arts; another, the myrrh-bearing country, and another the frankincense-bearing country, although the same countries produce cassia, cinnamon, and nard."

In the 1st century BC, the Arabian city of Eudaemon (usually identified with the port of Aden, and meaning "good spirit" in the sense of angelic beings), in Arabia Felix, was a transshipping port in the Red Sea trade. It was described in the Periplus of the Erythraean Sea (probably 1st century AD) as if it had fallen on hard times. Of the auspiciously named port we read in the periplus that