An Yle poll suggests that 53 percent of people in Finland would support an application to join the Nato military alliance.
Twenty-eight percent opposed an application, while 19 percent said they were unsure.
Taloustutkimus conducted the poll last week, as Ukraine came under attack by Russian forces. Interviews took place between February 23 and 25, spanning the opening days of the invasion.
Finland and neighbouring Sweden have an "enhanced partnership" with Nato, and took part in a Nato summit on Friday.
That same day, the Russian Foreign Ministry warned that "Finland’s accession to Nato would have serious military and political repercussions".
'Tectonic plates' moving on security policy
The poll represents a historic change in Finns' attitudes to Nato membership. Support is up by some 34 percentage points since 2017, when Yle last asked the question.
At that point just 19 percent of Finns supported Nato membership. Taloustutkimus last asked the question in January for commercial broadcaster MTV Uutiset, and at that point found support for Nato membership stood at 30 percent.
Juho Rahkonen, head of research at Taloustutkimus, said that there has been a radical change in Finnish views, with figures for support and opposition to Nato membership essentially swapping.
Supporters of the conservative National Coalition Party were keenest on membership, as expected, but there was a majority in favour among supporters of every party except the Left Alliance.
There was a major gender split, with 64 percent of men supporting membership, compared to just 41 percent of women. However that still represented a plurality of women as only 31 percent said they opposed joining.