On 1 January 1991, Finland joined CERN as the organization's 15th member state. The Finnish government ratified the CERN convention and deposited the formal accession papers with the Director-General of UNESCO on 28 December 1990. On 28 January 1991 a full delegation of Finnish politicians and scientists came to Geneva to celebrate the official hoisting of the Finnish flag in front of the CERN entrance. The Finnish delegation was led by Jaakko Numminen, Secretary-General of the Finnish Ministry of Education and Science, and Antti Hynninen, Finnish Ambassador to the United Nations.

Finland has a long-standing tradition of research in theoretical high-energy physics. Since the beginning of the 1980s, experimental research has focused on key experiments at the high-energy frontier. These activities range from the UA1 experiment at the CERN proton-antiproton collider, the DELPHI experiment at LEP and the CDF experiment at the Fermilab Tevatron to significant contributions to three LHC experiments: ALICE, CMS and TOTEM. In parallel, Finnish research groups participate in experiments at the ISOLDE facility. It was therefore logical that Finland joined CERN as a member state in 1991.

Present and future experimental activities are based on four cornerstones: the Helsinki Institute of Physics, which coordinates experimental HEP activities in Finland; a good laboratory infrastructure for semiconductor and gas detector construction and development; a strong local link between phenomenology and experiment, especially in the fields of new physics and quantum chromodynamics; and a good university education system. With the exception of CDF, all experimental and a large part of the phenomenological research are linked to CERN activities. 

The highest priority of the Finnish high-energy-physics community is a successful completion of the approved Large Hadron Collider (LHC) programme. In parallel, it pursues a strong interest in a physics programme with a high-luminosity upgrade of the LHC, and post-LHC facilities such as a linear electron-positron collider or a neutrino factory.