The earliest, documented windmills existed in Sistan, Persia, in the 7th century. These were vertical axle windmills, with six to twelve blades that were made from wood or bundles of reeds. They were used to mill grain and draw up water. Four hundred years later, in 1105, the first horizontal axis windmill, a post mill, was built in Europe. The first mention of a Chinese windmill for irrigation was made in 1219 in Mongolia at the time of Genghis Khan.

By the 14th century, Dutch windmills were used to drain and reclaim areas of the Rhine River delta. Between 1600 and 1700, thousands of windmills sprouted up in the Netherlands powering saw mills that supplied shipbuilders for the Dutch East India Company. In the rest of Europe, the use of wind turbines peaked between 1800 and 1900. At that time, over 200,000 windmills were in use, mainly for milling grain.

In 1854, Daniel Halladay invented a windmill for pumping water in the US. At the time of World War I, American windmill makers were producing 100,000 of these farm windmills each year. The first known electricity generating windmill was installed in 1887 by James Blyth in Scotland, UK to power lights in his holiday home. Scantly one year later in 1888, American Charles F. Brush built the first large (12 kW) windmill in Cleveland, Ohio to power lights and motors connected to an electric grid. In 1891, Poul La Cour, a Danish meteorologist, first incorporated aerodynamic design principles into wind turbines.

By the 1930s, farms in the United States that were not yet connected to the electrical grid commonly used windmills for electricity. Bulk-power, utility-scale wind energy conversion systems were first developed at Yalta, USSR in 1931 with the 100 kW Balaclava wind generator atop a 30 m (100 ft) tower, connected to the local 6.3 kV distribution system. In 1941, the 1.25MW, twin-blade Smith-Putnam turbine was the world's first megawatt wind turbine connected to the power grid in Vermont, USA.

Johannes Juul, a Danish engineer, pioneered the modern wind turbine design. The 200kW, three-bladed Gedser turbine constructed in 1957 inspired many later designs. Juul also invented the emergency aerodynamic tip breaks, which are still used in today's designs.