Genealogies and extracts from the church register can be ordered directly from the Orthodox Church of Finland’s central register (link to Finnish website)
You can order a certificate via the electronic form, telephone, fax or email.
The central register contains information concerning the Orthodox Parish of Helsinki, starting from the year 1827.
Military administration archives for parishes that were abolished after Finland’s independence can be found at the Mikkeli branch of the National Archives of Finland and in the digital archive.