Gustaf Nyström (21 January 1856 – 30 December 1917) was a Finnish architect. Nyström has been described as one of the most important architects in Finland at the end of the 19th century and the beginning of the 20th century. He was active both as an influential teacher, as an architect in his own right, and as an official involved in groundbreaking urban planning projects.
Nyström studied architecture at the Polytechnical school (today Helsinki University of Technology) and graduated in 1876. He also spent a year studying in Vienna under Heinrich von Ferstel in 1878–79. He began work in the office of his former teacher, Frans Anatolius Sjöström, and took over Sjöström's firm in 1885. Already in 1879 he started teaching construction at the Polytechnical Institute (as it had then become) and in 1885 was named senior teacher of architecture. This position was later transformed into a professorship, and Nyström thus became the first professor of architecture in Finland. He was the principal of the institution between 1895 and 1917, and contributed to the transformation of the Polytechnical Institute into a University of Technology in 1908. The Imperial Academy of Arts in Saint Petersburg honoured him with the title of "academician" in 1892. He was also a member of a national archaeological commission and was a proponent of careful and scientific building conservation.
Nyström has been described as a "legendary teacher of architecture" and as the foremost teacher of architecture in Finland for around 40 years. During this time he developed the curriculum from a one-sided focus on artistic qualities (e.g. through practicing architectural drawing) to also include elements of engineering. He continued to teach in the Classical tradition but also emphasised the local Nordic and Finnish expressions of architecture. In this way, he became an influential teacher of architects working in the National Romantic style, which was to become very popular in Finland around the turn of the century, although he himself was less interested in the style. He has been described as a thorough and intellectual teacher.