Oskar Bertil Petrus Jansson (29 June 1898 – 25 September 1981) was a Swedish athlete, who competed at the 1920 and 1924 Summer Olympics.

[2] Jansson won the Swedish shot put title in 1916 and 1918–1929.

[3][4][5] At the 1920 Olympic Games, Jansson competed in the shot put at the 1920 and finished in ninth place.

[2][6] Jansson won another British AAA shot put title at the 1921 AAA Championships and also finished third behind Benjamin Howard Baker in the high jump event at the same championships.

[7][8][9][1] Four years later at the 1924 Olympic Games, Jansson finished in eighth place during the shot put event.