Passengers arriving to Finland are not required to get testing for COVID-19, if they have a certificate of being given the full series of coronavirus vaccines, and at least two weeks have passed from the last vaccination.
In addition, passengers will not be required to get tested at the border, if they have a certificate that they have been infected by coronavirus disease and have received at least one dose of a coronavirus vaccine. When at least one week has passed from the coronavirus vaccine, they will be seen as a passenger with a full series of vaccines.
Also, passengers that have a certificate of having had one dose of a two-dose series of vaccines, and at least two weeks have passed since the most recent vaccination will not be required to get tested. Please note, that in spite of this, you should have a coronavirus test no earlier 72 hours after arriving in Finland.
Please find out more from the Finnish Institute for Health and Welfare: Travel and the Coronavirus Pandemic (THL)