Polling stations opened at 09:00 (06:00 GMT) and will close at 20:00 (17:00 GMT) when the results of some 1.7 million advance votes will be released.
Thousands of candidates from 22 political parties are vying for 200 seats in Finland’s one-chamber parliament, the Eduskunta.
The Social Democrats, Centre Party, National Coalition Party, and Finns Party are expected to dominate elections.
The 200 members of the Parliament of Finland (Eduskunta) were elected using open-list proportional representation in 13 multi-member constituencies, with seats allocated according to the D'Hondt method.
The number of elected representatives is proportional to the population in the district six months before the elections. Åland has a single-member electoral district and its own party system. (ILKHA)