Marilyn Bernice Renfree AO FAA FRS (born 19 April 1947) is an Australian zoologist.
She completed her PhD at the Australian National University, was a post-doctoral fellow in Tennessee and then Edinburgh before returning to Australia.
Marilyn Renfree was born in Brisbane, Queensland but moved to Canberra where her father was appointed Commonwealth Crown Solicitor.
Renfree went to Canberra Girls' Grammar School where she studied French, German, English, geography, maths and biology.
As part as her research, she showed that it was possible to reactivate embryos that were in embryonic diapause (a state of suspended animation) and carry them to full term by giving progesterone injections.
Renfree also proved that, during pregnancy, the two uteri of kangaroos and wallabies behave differently, the gravid one becoming larger than the non-pregnant one due to the presence or absence of the embryo.
Renfree moved back to Australia to take up a lecturer position in vertebrate biology at Murdoch University, Perth, WA in 1973.
Renfree established a colony of tammars at Murdoch University and also started working on agile wallabies, studying them to understand how lactation is controlled in marsupials.
In January 1982, Renfree married Roger Short and they both moved to Monash University, Melbourne, Victoria where she started her third tammar colony.
She was awarded the Gold Conservation Medal of the Zoological Society of San Diego for 2000, the Commonwealth of Australia's Centenary Medal in 2003, and was made an Officer of the Order of Australia (AO) in 2013 "for distinguished service to biology, particularly through leadership in the research into marsupial reproduction, and to the scientific community".
[citation needed] Another link to science was Renfree's sister, Bev, who was Frank Fenner's technician.