Ruth Ann Sanger FRS was an Australian haematologist and serologist. She worked closely with R.R. Race from the 1940s, and they married in 1956. They were co-authors many papers after 1948, and co-wrote six editions of a leading work on blood groups, Blood Groups in Man, known as "Race and Sanger", which were published between 1950 and 1975.
Sanger was born in Southport, Queensland, Australia. Her father became headmaster of Armidale School in New South Wales. She was educated at Abbotsleigh School in Sydney, and graduated from Sydney University in 1938. After working as a haematologist for the Red Cross Blood Transfusion Service in Australia, she moved to England in 1946 to work with Race, and received a doctorate from the University of London in 1949 on the variety of blood group systems. She returned to Australia after receiving her doctorate, but then moved permanently to the UK in 1950. The first edition of Blood Groups in Man was published in August 1950, based on the systematic analysis of blood groups in her PhD thesis.
After Race's first wife died in 1955, she married Race in April 1956. In 1973, she followed Race as director of the Medical Research Council's blood group unit at the Lister Institute in London. She retired in 1983.