Gamesa began operations in 1976 as Grupo Auxiliar Metalúrgico S.A., focused at that time on developing new technologies and applying them to emerging activities. These included robotics, microelectronics, aeronautics and the development of composite materials. It was founded by Juan Luis Arregui and Joseba Mikel Grajales.
In 1994, Gamesa Eólica was created as a subsidiary specializing in the manufacture of wind turbines. The company became involved in the development, construction and operations of wind farms in 1995 and completed its first wind farm the following year. Gamesa had a 7-year partnership with Vestas that ended in 2002.
The corporation was officially listed on the stock exchange on 31 October 2000 and joined the selective IBEX 35 on 24 April 2001. In 2002, Gamesa acquired gearboxes manufacturer Echesa, generators manufacturer Cantarey, and converters manufacturer Enertrón.
Since 2006, the company has focused on technologies associated with sustainable energy, principally wind power. It has divested of its interests in aeronautics, which were sold off to form a new company known as Aernnova, and in services, which were sold off to form a new company known as Global Energy Services.
As part of the United Kingdom's move to expand its production of offshore wind energy production, Gamesa has committed to the expenditure of £133.7 million on a production factory and other facilities in the UK, and will also move its offshore wind division headquarters to London.
In January 2014, Gamesa and French nuclear manufacturer Areva announced a preliminary deal to create a joint venture Adwen in the offshore wind power business. In early 2015 Gamesa continued its expansion of UK services by acquiring B9 Energy.
In 2017, Areva sold its stake in Adwen to Gamesa, after the merger of Gamesa and Siemens Wind Power was announced.