When Ole Østensen was born on 11 June 1756, in Vågå, Oppland, Norway, his father, Øystein Mårheim Olsson, was 33 and his mother, Anne Trulsdatter, was 25. He married Elen Halvorsdatter on 2 January 1776, in Tinn, Telemark, Norway. They were the parents of at least 3 sons and 2 daughters. He died on 30 December 1808, in Tinn, Telemark, Norway, at the age of 52.