Ichiji Tasaki (田崎 一二, Tasaki Ichiji, October 10, 1910 – January 4, 2009) was a Japanese-born American biophysicist and physician involved in research relating to the electrical impulses in the nervous system. Tasaki is credited with discovering the insulating function of the myelin sheath. His discoveries provided the foundation for a better understanding of diseases such as multiple sclerosis, in which myelin is lost or damaged.