The Nurek Dam (Tajik: Нерӯгоҳи обии Норак, Nerūgohi obii Norak, Tajiki for Nurek Hydro-electric Station) is an earth fill embankment dam on the Vakhsh River in the central Asian nation of Tajikistan. Construction of the dam began in 1961 and was completed in 1980, when Tajikistan was still a republic within the Soviet Union. At 300 m (984 ft) it is currently the tallest dam in the world. The Rogun Dam, also along the Vakhsh also in Tajikistan, may exceed it if completed.

The Nurek Dam was constructed by the Soviet Union between the years of 1961 and 1980. It is uniquely constructed, with a central core of cement forming an impermeable barrier within a 300 m (980 ft)-high rock and earth fill construction. The volume of the mound is 54 million m³. The dam includes nine hydroelectric generating units, the first commissioned in 1972 and the last in 1979.

The dam is located in a deep gorge along the Vakhsh River in western Tajikistan, about 75 km (47 mi) east of the nation's capital of Dushanbe. A town near the dam, also called Nurek, houses engineers and other workers employed at the dam's power plant.

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations.

The word dam can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities. Early dam building took place in Mesopotamia and the Middle East. Dams were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers, and could be quite unpredictable.

The earliest known dam is the Jawa Dam in Jordan, 100 kilometres (62 mi) northeast of the capital Amman. This gravity dam featured a 4.5 m (15 ft) high and 1 m (3 ft 3 in) wide stone wall, supported by a 50 m (160 ft) wide earth rampart. The structure is dated to 3000 BC. The Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, located about 25 km (16 mi) south of Cairo, was 102 m (335 ft) long at its base and 87 m (285 ft) wide. The structure was built around 2800 or 2600 B.C. as a diversion dam for flood control, but was destroyed by heavy rain during construction or shortly afterwards. By the mid-late third century BC, an intricate water-management system within Dholavira in modern day India, was built. The system included 16 reservoirs, dams and various channels for collecting water and storing it.