When Gabriel Østensen was born on 1 February 1717, in Kvinnherad, Hordaland, Norway, his father, Øystein Øysteinsen Omvik, was 42 and his mother, Maddel Henningsdtr Hauge, was 29. He married Lisbet Larsdotter Josnes on 3 November 1748, in Kvinnherad, Hordaland, Norway. They were the parents of at least 4 sons and 4 daughters. He died in 1782, in Landa, Kvinnherad, Hordaland, Norway, at the age of 65.