The Finnish Parliament House designed by J. S. Siren is regarded as the pinnacle of Finnish construction of its time. The monumental building has been sculpted to form a carefully considered whole from its crafted façade down to custom designed furniture.

The building is a result of a protracted series of architectural competitions, the first of which was arranged in 1908 for a different site, on Tähtitorninmäki Hill. Eliel Saarinen won the first prize but the construction was rejected by the Russian tsar.  After Finland gained independence in 1917 debate about the building resumed and continued until a site placement competition organised in 1923 helped resolve the decision to build in Töölö.

An open architectural competition was held the following year. Of the 27 entries the design by Kaarlo Borg, J. S. Sirén and Urho Åberg was declared winner. It was the basis of the final plans executed by J. S. Siren. The building was inaugurated in 1931.

Two more open architectural competitions were held later on to design extensions for the Parliament House, the first one in 1970 and behind the main building, won by Ola Laiho, Pekka Pitkänen and Ilpo Raunio, and in 1999 the nearby annex Pikkuparlamentti (Little Parliament), won by Pekka Helin.

The Parliament House has undergone extensive renovation and restoration work that lasted for a decade and completed in September 2017. The architect in charge of the works was Helin & Co Architects.