Kristian Gullichsen is a Finnish architect. The son of Harry and Maire Gullichsen he was born into a family of industrialists, designers and artists. Kristian Gullichsen has been a member of the board of governors of the Alvar Aalto Academy and the committee of the Alvar Aalto Symposium. From 1988 to 1993 he held the title of Finnish State Artist Professor.

Kristian Gullichsen studied architecture at Helsinki University of Technology, qualifying as an architect in 1960, after which he returned to the Aalto office to work as an assistant architect, before founding his own office in 1961. From 1965 to 1967 he was also Head of the Exhibitions Office of the Museum of Finnish Architecture, Helsinki. In his early career he did a number of joint works with other architects such as Kirmo Mikkola and Juhani Pallasmaa. Of such projects the most memorable historically was the so-called Moduli 225 house (1969-1971), an industrially produced prefabricated summer house, built in timber, steel and glass, influenced by Japanese house design, the teachings of his mentor, Finnish architect and professor, Aulis Blomstedt and the minimalist houses of Mies van der Rohe. Seventy of the houses were built, but few remain today because they could not withstand the Finnish climate.

In 1969 Gullichsen founded a partnership in Helsinki with architects Erkki Kairamo and Timo Vormala, Arkkitehdit KY, which continued until Kairamo's death in 1997. The three partners presented different architectural modernist styles, Gullichsen the monumental, Kairamo the constructivist and Varmola the typological. Since Kairamo's death Gullichsen and Vormala have continued together as Gullichsen Vormala Arkkitehdit.

The work of the office reached international attention in the late 1970s and early 1980s, described by the British journal The Architectural Review as constituting the "Cool Helsinki School". Gullichsen's mature architecture can be seen as a late-modernist style, combining the minimalist aesthetic of pure modernism with the humanist touches and concern for locality, craftsmanship and materials derived from Aalto.