The Beqaa Valley (Arabic: وادي البقاع, Wādī l-Biqā‘, Lebanese [bʔaːʕ]), also transliterated as Bekaa, Biqâ, and Becaa and known in classical antiquity as Coele-Syria, is a fertile valley in eastern Lebanon. It is Lebanon's most important farming region. Industry also flourishes in Beqaa, especially that related to agriculture.

The Beqaa is located about 30 km (19 mi) east of Beirut. The valley is situated between Mount Lebanon to the west and the Anti-Lebanon Mountains to the east. It is the northern continuation of the Jordan Rift Valley, and thus part of the Great Rift Valley, which stretches from Syria to the Red Sea. Beqaa Valley is 120 kilometres (75 mi) long and 16 kilometres (9.9 mi) wide on average. It has a Mediterranean climate of wet, often snowy winters and dry, warm summers.

The region receives limited rainfall, particularly in the north, because Mount Lebanon creates a rain shadow that blocks precipitation coming from the sea. The northern section has an average annual rainfall of 230 millimetres (9.1 in), compared to 610 millimetres (24 in) in the central valley. Nevertheless, two rivers originate in the valley: the Orontes (Asi), which flows north into Syria and Turkey, and the Litani, which flows south and then west to the Mediterranean Sea.

From the 1st century BC, when the region was part of the Roman Empire, the Beqaa Valley served as a source of grain for the Roman provinces of the Levant. Today the valley makes up 40 percent of Lebanon's arable land. The northern end of the valley, with its scarce rainfall and less fertile soils, is used primarily as grazing land by pastoral nomads. Farther south, more fertile soils support crops of wheat, maize, cotton, and vegetables, with vineyards and orchards centered on Zahlé. The valley also produces hashish and cultivates opium poppies, which are exported as part of the illegal drug trade. Since 1957 the Litani hydroelectricity project, a series of canals and a dam located at Lake Qaraoun at the southern end of the valley, has improved irrigation to farms in Beqaa Valley.