Born in Baarn as Fanny Koen, she didn't start competing in athletics until she was 16 years old. At the track, she met coach Jan Blankers (a Olympic former triple jumper), who would later become her husband. She appeared to be a very versatile athlete, and was sent out to the 1936 Summer Olympics in Berlin at age 18. There she performed well, finishing 5th in the high jump and 5th with the Dutch 4 x 100 m relay team.
Although World War II made international competition impossible, she set several World Records in 1943, not long after having become a mother.
For the 1948 Summer Olympics, however, she was considered too old by the press to be a real favourite. Blankers-Koen was even more motivated after reading this, and she went on to win four gold medals in an overwhelming fashion: the 100 m, 200 m, 80 m hurdles and the 4 x 100 m. Some believe that Blankers-Koen, World Record holder in the high jump, long jump and pentathlon at the time, could have won more medals had she competed in these events, but Blankers-Koen herself indicated she wouldn't have had the strength to compete in all these events.
Now known as the "Flying housewife", she continued her career with some success, winning European titles in 1950 and setting a World Record in 1951. At the 1952 Summer Olympics, she abandoned the 80 m hurdles final shortly after the start, but she would continue to compete in athletics until 1955.
In 1999, the IAAF awarded Fanny Blankers-Koen with the title of "Female athlete of the century".