Harvia Plc (natively Harvia Oyj) is a Finnish heater, sauna, spa and sauna interiors manufacturer. The company's product offering covers all three sauna types: traditional sauna, steam sauna and infrared sauna. Harvia is headquartered in Muurame, Central Finland. The company's products are distributed globally through a network of dealers. Harvia shares (“HARVIA”) are listed on the Nasdaq Helsinki Ltd and are registered in the Finnish Book-Entry Register maintained by Euroclear Finland Ltd.

In 2018, Harvia ranked as the third largest sauna company globally.

In 1950, Tapani Harvia founded the Art Workshop Harvia (named Taidetakomo Harvia) in Jyväskylä, located on the ground floor of his private residence. The company manufactured decorative items, including hearth doors.

Tapani Harvia made the first Harvia woodburning stove for his own use in 1950. The first woodburning stove for sale was completed in the mid-1950s. By the end of the decade sauna heaters had become Harvia's main product with about 500 sold annually. In 1958 the company was renamed Takomo T Harvia Ky and in 1961 it was renamed Harvia Ky.

In the early 1960s, the production of continuously heated heaters began. By the decade's end, Harvia manufactured about a thousand heaters a year.

Harvia moved from Jyväskylä to Muurame in 1972 to its own industrial hall. Harvia's adult kids joined the company in the mid-1970s. Risto Harvia started as CEO in 1977.

Harvia Ky changed from being a limited liability company to Harvia Oy in 1980. Tapani Harvia retired and served as chairman of the board. In addition to wood-burning stoves, Harvia began manufacturing electric stoves in the early 1980s. In the end of the decade the company manufactured approximately 20,000 wood-fired and 5,000 electric heaters per year.

Growth continued in the 1990s, when the company started exporting to Central Europe, Eastern Europe, Russia and the United States.