A son of a fisherman, Johan Richthoff participated in football and athletics. When a new club was formed in his neighborhood he started practicing wrestling. He was ranked fourth in 1924 before he won gold medals in 1928 and 1932 in heavyweight freestyle. In 1929 and 1930, he was European champion in light-heavyweight freestyle, also winning in 1930 in Greco-Roman. Domestically Richthoff won eight Swedish Championships. For his two European titles he was awarded the Svenska Dagbladet Gold Medal in 1930. After the 1932 Games he turned professional in the United States, remaining undefeated in 100 bouts. He later coached Sweden’s freestyle wrestlers at the 1936 Olympics, although he continued to wrestle professionally until age 49. He devoted himself to the fight against alcohol as a Free Church preacher. He was also active in music, literature, and as a chess player.