Ray David Owen (October 30, 1915 – September 21, 2014) was a teacher and scientist whose discovery of unusual, “mixed,” red blood cell types in cattle twins in 1945 launched the fields of modern immunology and organ transplantation.

[7] In 1941 Owen received a PhD in genetics from the University of Wisconsin–Madison, where he continued to work as a postdoctoral researcher and assistant professor for several years.

[6] As a postdoctoral fellow in the Immunogenetics Laboratory at the University of Wisconsin, Owen's research interests moved from fowl to cattle.

[3] This eventually led to Burnet and Medawar's 1960 Nobel Prize in Physiology or Medicine for the discovery of acquired immunological tolerance.

He co-authored papers that described “the use of radiation as a means of blocking or resetting the immune system before transplantation of bone marrow or other tissues.”[4] Caltech offered Owen an assistant professorship in biology in 1947.

While Owen maintained an active research program, his teaching, mentoring and administrative undertakings became an important part of his academic career.

[1][3][8] In an interview with the University of Wisconsin, Owen's son David opined that his father's rural upbringing influenced his career in many ways –- his work ethic, his skill at working with animals, and his support for women, minorities and other who faced undue obstacles on the path to careers in science.