The Saka (Old Persian: ; Kharoṣṭhī: 𐨯𐨐 ; Ancient Egyptian: , ; , old , mod. , ), Shaka (Sanskrit (Brāhmī): , , ; Sanskrit (Devanāgarī): शक , शाक ), or Sacae (Ancient Greek: ; Latin: ) were a group of nomadic Eastern Iranian peoples who historically inhabited the northern and eastern Eurasian Steppe and the Tarim Basin.
The Sakas were closely related to the European Scythians, and both groups formed part of the wider Scythian cultures and ultimately derived from the earlier Andronovo culture, and the Saka language formed part of the Scythian languages. However, the Sakas of the Asian steppes are to be distinguished from the Scythians of the Pontic Steppe; and although the ancient Persians, ancient Greeks, and ancient Babylonians respectively used the names "Saka," "Scythian," and "Cimmerian" for all the steppe nomads, the name "Saka" is used specifically for the ancient nomads of the eastern steppe, while "Scythian" is used for the related group of nomads living in the western steppe; While the Cimmerians were often described by contemporaries as culturally Scythian, they may have differed ethnically from the Scythians proper, to whom the Cimmerians were related, and who also displaced and replaced the Cimmerians.
Prominent archaeological remains of the Sakas include Arzhan, Tunnug, the Pazyryk burials, the Issyk kurgan, Saka Kurgan tombs, the Barrows of Tasmola and possibly Tillya Tepe. In the 2nd century BC, many Sakas were driven by the Yuezhi from the steppe into Sogdia and Bactria and then to the northwest of the Indian subcontinent, where they were known as the Indo-Scythians. Other Sakas invaded the Parthian Empire, eventually settling in Sistan, while others may have migrated to the Dian Kingdom in Yunnan, China. In the Tarim Basin and Taklamakan Desert of today's Xinjiang Uyghur Autonomous Region, they settled in Khotan, Yarkand, Kashgar and other places.
Linguist Oswald Szemerényi studied synonyms of various origins for Scythian and differentiated the following terms: , , , and .