Jakob Frans Oskar Wasastjerna (1819âÂÂ1889), known as Oskar Wasastjerna, was a Finnish soldier, civil servant, genealogist, historian, writer and member of the .
Jakob Frans Oskar Wasastjerna was born on 15 October 1819 in Vähäkyrö (present-day, Vaasa) to Frans Didrik Wasastjerna and Hedvig Elisabet Banger.
In 1859, Wasastjerna was the district manager of the Eastern Customs District of Finland. In 1867, Wasastjerna was a customs officer of Porvoo.
Wasastjerna was married to Johanna Beata Nordenborg and Maria Margaretha Mether. Wasastjerna had five children, including Karl Oskar Wasastjerna (1853âÂÂ1923) a captain, author and member of the Diet of Finland. On 21 February 1889, Wasastjerna died aged 69 in Porvoo.