Valmet traces its origins back to the industrial plants established in the 1920s and 1930s to meet the needs of the Finnish Armed Forces. During the 1950s the company began to broaden its product range to accommodate the demands of a market economy. The product range expanded over the years to include ships, aircraft, weapons, locomotives, tractors, marine engines, elevators and, of course, paper machines. Valmet delivered its first paper machine in 1953 and over the years, Valmet became a well-known brand in the pulp & paper industry.
In the 1980's and 1990's, Valmet focused increasingly on paper technology. Valmet sold its shipbuilding industry, and the manufacture of rolling stock, elevators and tractors. In turn, Valmet bought Wärtsilä's paper finishing machinery unit, the Swedish company Karlstads Mekaniska Werkstad (KMW) and the board machine manufacturer Tampella Papertech.
Metso Corporation was created as the result of a merger between Valmet and Rauma in 1999. Metso Paper was formed by merging Valmet Corporation's paper technology and Sunds Defibrator's fiber technology operations. Metso's fiber and paper technology business area was known as Valmet until the name was changed to Metso Paper in 2001. Intellectual property rights of the trademark Valmet are owned by Metso Paper.