Sam Eyde photographed in 1910
|Born||29 October 1866|
|Died||21 June 1940 (aged 72)|
|Known for||Birkeland-Eyde process|
Eyde was born in Arendal in Aust-Agder, Norway. He was a son of ship-owner Samuel Eyde (1819–1902) and his wife Elina Christine Amalie Stephansen (1829–1906). He was a first cousin of Alf Scott-Hansen on the maternal side.
In August 1895 he married Countess Ulla Mörner (1873–1961), but the marriage was dissolved in 1912. In February 1913 he married actress Elly Simonsen (1885–1960).
Eyde studied engineering in Berlin where he graduated in 1891. He started his career in Hamburg, working with the railways where he planned new lines, bridges and stations. In 1897 he started the engineering firm Gleim & Eyde with his previous boss from Hamburg. He soon established offices in Kristiania (now Oslo) and Stockholm. By the turn of the century the firm was one of the largest in Scandinavia, with some 30 engineers.
In 1902, Eyde acquired control over Rjukan Falls in Telemark. He also held rights to waterfalls at Arendal and Notodden. Eyde planned to use the hydropower for industrial purposes. In 1905 Rjukan Falls was producing hydro electrical power for Potassium nitrate production. This led to the development of the town of Rjukan as an industrial centre. In 1912 Eyde contributed to the development of Arendal Smelteverk at Eydehavn for the production of silicon carbide. 
In 1903, Eyde met with Kristian Birkeland, who was a scientist, inventor and professor of physics at the University of Christiania. Birkeland was working on developing an electric arc, while Eyde had recently bought the rights to several waterfalls in Telemark. They agreed to cooperate to develop an electric flame. This allowed Eyde to establish Det Norske Aktieselskap for Eletrokemisk Industri (today Elkem) along with members of the Wallenberg family who he had met in Sweden. The factory at Notodden opening on 2 May 1905. 
In 1905 he founded Norsk Hydro-Elektrisk Kvælstofaktieselskab (now Norsk Hydro). Eyde remained director-general of both companies.He was director-general of Norsk Hydro until 1917. He was offered a position on the board, where he remained until 1925, and a compensation of 250,000 kr for ten years, and 100,000 kr for the rest of his life.
- "Portrett av en ung Sam Eyde". avtrykk.no. Retrieved August 1, 2017.
- Grimnes, Ole Kristian. "Sam Eyde". In Helle, Knut. Norsk biografisk leksikon (in Norwegian). Oslo: Kunnskapsforlaget. Retrieved 28 March 2012.
- Norland, Andreas (4 November 1972). "Sam Eyde. Eventyrgutten som skapte to byer". A-magasinet (in Norwegian). p. 19.
- Payton, Gary & Lepperød, Trond (1995). Rjukanbanen; på sporet av et industrieventyr (in Norwegian). Rjukan: Mana Forlag. pp. 20–24.
- "Sam Eyde". Store norske leksikon. Retrieved August 1, 2017.
- Bård Raustøl. "A/S Arendal Smelteverk - bedriftshistorie". Aust-Agder kulturhistoriske senter. Archived from the original on December 15, 2007. Retrieved August 1, 2017.
- "Kristian Birkeland". The Plasma Universe theory. Retrieved August 1, 2017.
- "Three remarkable men". yara.com. Archived from the original on 2017-08-21. Retrieved August 1, 2017.
- Sam Eyde: Mitt Liv og Mitt Livsverk (Gyldendal 1939) pp 439-448
- Norsk Industriarbeidermuseum (2006-04-07). "Sam Eyde 1917" (in Norwegian). Retrieved 2008-06-20.[permanent dead link]
- "Norway minister arrives". The Washington Post. 31 December 1920. p. 6.
| Director-general of Norsk Hydro