Gustaf Dyrssen (24 November 1891 – 13 May 1981) was a Swedish army officer, modern pentathlete and Olympic champion. He competed at the 1920 Summer Olympics in Antwerp where he received a gold medal in modern pentathlon. He received a silver medal at the 1924 Summer Olympics in Paris.
He participated on the Swedish fencing team at the 1936 Summer Olympics in Berlin, where the team received a silver medal in épée.
After his athletic career, he held several leading role in Swedish sports. He was also President of the International Modern Pentathlon Union (IUPM) from 1949 to 1960 and member of the International Olympic Committee from 1952 to 1970.
In his army career, Dyrssen was the commandant of Boden Fortress from 1942 to 1944 and superior commandant of Stockholm from 1945 to 1957. He was promoted to Lieutenant General in 1957.