Rosalyn Sussman Yalow, American physicist and academic, Nobel Prize laureate (born 1921)

Rosalyn Sussman Yalow was an American medical physicist, and a co-winner of the 1977 Nobel Prize in Physiology or Medicine for development of the radioimmunoassay technique. She was the second woman, and the first American-born woman, to be awarded the Nobel Prize in Physiology or Medicine.

The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, according to Alfred Nobel's 1895 will, are awarded "to those who, during the preceding year, have conferred the greatest benefit to humankind". Nobel Prizes are awarded in the fields of Physics, Medicine or Physiology, Chemistry, Literature, and Peace.