The Fergana Valley or Farghana Valley (Uzbek: Farg‘ona vodiysi, Kyrgyz: Фергана өрөөнү [ferʁana œrœːny], Tajik: водии Фaрғонa, Russian: Ферганская долина, Persian: وادی فرغانه‎) is a region in Central Asia spread across eastern Uzbekistan, Kyrgyzstan and Tajikistan. Divided into three subdivisions of the former Soviet Union, the valley is ethnically diverse, and in the early 21st century was the scene of ethnic conflict. A large triangular valley in what is an often dry part of Central Asia, the Fergana owes its fertility to two rivers, the Naryn and the Kara Darya, which run from the east, joining near Namangan, forming the Syr Darya river. The valley's history stretches back over 2300 years, when its population was conquered by Greco-Bactrian invaders from the west. Chinese chroniclers date its towns to more than 2100 years ago, as a path between Greek, Chinese, Bactrian and Parthian civilizations. In the path of the Northern Silk Road, the area was converted by Muslim invaders from the west, and was home to Babur, famous conqueror and founder of the Mughal Empire in India, tying the region to modern Afghanistan and South Asia. The Russian Empire conquered the valley at the end of the 19th century, and it became part of the Soviet Union from the beginning of the 20th. Its three soviet regional states gained independence in 1991. The area remains Muslim, populated by ethnically Uzbek, Tajiks, and Kyrgyz, often intermixed and not matching modern borders. As well there historically have been substantial Russian, Kashgarians, Kipchaks, Bukharan Jews and Romani minorities. Mass cotton cultivation, introduced by the Soviets, remains central to the economy, along with a wide range of grains, fruits and vegetables. There is a long history of stock breeding, leatherwork, and a growing mining sector, including deposits of coal, iron, sulfur, gypsum, rock-salt, lacustrine salt, naphtha, and some small known oil reserves.

Coordinates: 40°23′11″N 71°47′11″E / 40.38639°N 71.78639°E / 40.38639; 71.78639 Fergana (Uzbek: Farg'ona/Фарғона; Persian: فرغانه‎ Farghāneh; Russian: Фергана́) is a city (population: 214,000), the capital of Fergana Province in eastern Uzbekistan, at the southern edge of the Fergana Valley in southern Central Asia, cutting across the borders of Kyrgyzstan, Tajikistan, and Uzbekistan. Fergana is about 420 km east of Tashkent, and about 75 km west of Andijan.

The fertile Fergana Valley was an important conduit on the Silk Roads (more precisely the North Silk Road), which connected the ancient Chinese capital of Xi'an to the west over the Wushao Ling Mountain Pass to Wuwei and emerging in Kashgar before linking to ancient Parthia, or on to the north of the Aral and Caspian Seas to ports on the Black Sea.

The ancient kingdom referred to as Dayuan (大宛, "Great Yuan", literally "Great Ionians") in the Chinese chronicles is now generally accepted as being in the Ferghana Valley. It is sometimes, though less commonly, written as Dawan (大宛). Dayuan were Greeks, the descendants of the Greek colonists that were settled by Alexander the Great in Ferghana in 329 BCE, and prospered within the Hellenistic realm of the Seleucids and Greco-Bactrians, until they were isolated by the migrations of the Yuezhi around 160 BCE. It has been suggested that the name "Yuan" was simply a transliteration of the words “Yona”, or “Yavana”, used throughout antiquity in Asia to designate Greeks (“Ionians”). Their capital was Alexandria Eschate.