Transoxiana or Transoxania ("Land beyond the Oxus") is the Latin name for a region and civilization located in lower Central Asia roughly corresponding to modern-day eastern Uzbekistan, western Tajikistan, parts of southern Kazakhstan, parts of Turkmenistan and southern Kyrgyzstan. Geographically, it is the region between the rivers Amu Darya to its south and the Syr Darya to its north.
Historically known in Persian as (فرارود, fæɾɒːˈɾuːd̪ – 'beyond the [Amu] river'), (Фарорӯд), and (Варазрӯд), the area had been known to the ancient Iranians as Turan, a term used in the Persian national epic Shahnameh. The corresponding Chinese term for the region is Hezhong (). The Arabic term (ما وراء النهر, ˈmaː waˈraːʔ anˈnahr, which means "what is beyond the [Jayhūn] river") passed into Persian literary usage and stayed on until post-Mongol times.
The region of Transoxiana was one of the satrapies (provinces) of the Achaemenid Empire of Persia under the name Sogdia. It was defined within the classical world of Persia to distinguish it from Iran proper, especially its northeastern province of Khorasan, a term originating with the Sasanians, although early Arab historians and geographers tended to subsume the region within the loosely defined term "Khorasan" designating a much larger territory. The territories of Khwarazm, Sogdiana, Chaghaniyan, and Khuttal were located in the southern part of Transoxiana; Chach, Osrushana, and Farghana were located in the northern part.
The name Transoxiana stuck in Western consciousness because of the exploits of Alexander the Great, who extended Greek culture into the region with his invasion in the 4th century BCE. Alexander's successors would go on to found the Greco-Bactrian Kingdom, ushering in a distinct Greek cultural presence within Transoxiana that existed for over two hundred years. The city of Ai-Khanoum, situated on the Oxus in northern Afghanistan, remains the only Graeco Bactrian city to have been found and extensively excavated.