Sigurd Frosterus (4 June 1876 – 2 March 1956) was a Finnish architect, art critic and art collector.
Born in Asikkala, Frosterus graduated from Helsinki University with a degree in art history in 1899, and earned a diploma of architecture in 1902 at Polytechnical Institute.[1] In 1920 he earned his doctorate at the University with a dissertation on the use of colour in art.[2]
Frosterus had an architectural office in 1902–1904 with Gustaf Strengell and in 1918–1935 with Ole Gripenberg.[2] Frosterus and Strengell designed villas and manor houses, including Tamminiemi, which was an official residence of the President of Finland from 1940 until 1981.[1]
Frosterus's best-known work is the Stockmann department store in Helsinki. The architecture competition was held in 1916, but the building was not finished until 1930.[2]
Frosterus inspired numerous Finnish artists with his art theories and criticism. He collected post-impressionist art.[3]
Frosterus was the editor of Arkkitehti magazine in 1908–1911, and published books on art theory. He was also a talented watercolour painter.[2]