National Coalition Party candidate Alexander Stubb, left, and Social Movement candidate Pekka Haavisto attend a Presidential election event, at the Helsinki City Hall, in Helsinki, Finland, Sunday, Feb. 11, 2024. AP
The former leader of the National Conservative Party's bid for the office was prompted by Russia's invasion of Ukraine.
"I can say, hand on heart, that consideration was not reality before the war began", he said when announcing his candidacy in August. "When the fatherland calls, you go."
"I believe that one of the most important tasks for the next presidential term is to work for the preservation of the rule-based international system," Stubb said.
Upon winning the election, Stubb said becoming president was the "the greatest honour of my life."
With 98 percent of votes counted in Sunday's run-off.Stubb had 51.7 percent. His opponent Pekka Haavisto conceded.
Stubb was propelled to the heart of Finnish politics by chance, as the then MEP replaced party colleague Ilkka Kanerva as foreign minister in 2008 after the latter was forced to resign over a series of text messages to an erotic dancer.
Leaving Brussels behind, Stubb initially moved back into his childhood home in Helsinki, and has said that he was likely the world's only foreign minister to live with their father.
Stubb then served as prime minister from 2014 to 2015.
To NATO's core
The president elect has told Finnish media that as a new NATO member, Finland should "go to the core of NATO and to "produce, not consume, safety".
Finland dropped decades of military non-alignment and applied for membership in the military alliance in the wake of Russia's 2022 invasion of Ukraine -- though Stubb had already been a long-time supporter of a NATO bid.
In his forties, Stubb took up triathlon, and his enthusiasm for sport also made its mark on the foreign ministry where pastries and coffee were replaced by fruit and health drinks.
However, the 55-year-old put competitions on pause to focus on the race for president.
During his term as prime minister, he came under fire from the media for wearing shorts to a press conference concerning the situation in Ukraine in 2014 and for acting as a human dartboard in a theme park.
According to Stubb himself, one of his biggest mistakes as prime minister was to grant permission to the construction of a nuclear power plant together with Russia's state-owned Rosatom.
His career hit a snag after his party came second in 2015 elections and he switched to the role of minister of finance.
He then lost the leadership of his party to now-prime minister Petteri Orpo, and in 2017 he left the Finnish parliament to become vice president of the European Investment Bank.
After losing the race for the EU Commission presidency in 2018, Stubb left politics for academia, and has spent the past three years as director of the School of Transnational Governance at the European University Institute and professor in Florence, Italy.
A father of two, Stubb married Suzanne Innes-Stubb, currently head of global compliance at elevator engineering company Kone, in 1998.
A Finnish-British dual national, she will be the first foreign-born first lady in Finland.
Stubb became a sought-after commentator in foreign media after Russia's invasion of Ukraine in 2022, highlighting how in 2008 he had predicted that the war between Russia and Georgia would mark a turning point in foreign policy.
Stubb has lived in the US, France, the UK, Belgium, Luxemburg and Italy, and says he can hold negotiations in "excellent" Finnish, Swedish, English and French and "good" German.
The presidency means that once again, he will move back to Finland.