Oscar was born January 24, 1931 at Elrose, Saskatchewan. He attended Hester School until grade 8 then began farming with his father and brother Fred. He went to welding school for a few months as a teenager. He used this skill a lot. He sometimes duck hunted with Uncle Fred at Oyen, AB. Oscar married Katherine Mary Miller on October 26, 1962. They had three children; Irene, Josanne and Melba. Oscar loved gardening and cats. He was very home oriented and loved singing and playing the harmonica.
Oscar was predeceased by his parents Karl Jarman Johnson (1950) and Martha Johnson (1995); his daughter Melba (2004); and his wife Katherine (2005). He was also predeceased by brother Fred Johnson; sister Jennifer Thomas and younger sister Gladys Boyachek.
He is survived by daughter Josanne (Dan) Thiessen; stepdaughter Irene (Rod Scott) Miller; granddaughter Justine Johnson; and nieces Martha Boyachek, Karen Boyachek, Micheline Boyachek, Gwen (Rick) Bart and Rebecca Preciado; and nephews Larry (Evelyn) Thomas, Ben Boyachek, Mark Johnson and Chris Johnson.