Alexander Stubb has become the country's next president following a closely fought run-off vote.
The former prime minister will be taking on the role as Finland navigates its new NATO membership, spurred on by Russia's invasion of Ukraine.
Mr Stubb is taking over from hugely popular President Sauli Niinisto, who isn't eligible for re-election while his second six-year term expires next month.
Unlike in most European countries, the president of Finland holds executive power in formulating foreign and security policy together with the government.
They also command the military, although they are expected to remain above the fray of day-to-day politics.
Finish news outlets said Mr Stubb is coming into power at a time when Europe's security is at stake.
"Mr Stubb will become a president of difficult times, possibly even a wartime president," Finnish newspaper Ilta-Sanomat said in an editorial.
Speaking at a news conference in Helsinki, the newly elected leader said Finland has "one of the strongest military forces in Europe".
"We will play our part in the alliance [NATO]. People trust us and they know that we are serious about our defence for rather obvious reasons. Will I be an active commander-in-chief? Yes, I intend to do that," he said.
