Johan Gunnar Jansson (13 October 1897 – 15 December 1953) was a Swedish hammer thrower who competed at two Olympic Games.

[1][3] Jansson finished second behind fellow Swede Ossian Skiöld in the hammer throw event at the 1931 AAA Championships.

[4][5][6] He competed at the 1932 Summer Olympics, finishing in 7th in the hammer throw event.

[1][7] Jansson won a bronze medal at the 1934 European Championships before going to his second Olympic Games, finishing 12th in the hammer throw event at the 1936 Summer Olympics.

[8] This biographical article relating to Swedish athletics is a stub.