Mary Margaret Hagedorn (born September 12, 1954) is a US marine biologist specialised in physiology who has developed a conservation program for coral species, using the principles of cryobiology, the study of cellular systems under cold conditions, and cryopreservation, the freezing of sperm and embryos.

[1] Mary Hagedorn grew up in Long Island Sound, Connecticut, where she developed an interest in oceans and sea life.

She received her bachelor's and master's degrees in Biology from Tufts University, and she earned her Ph.D. in Marine Biology from the Scripps Institution of Oceanography of the University of California at San Diego.

[2] After a trip to the Amazon left two of her colleagues dead, Hagedorn reached a turning point in her career.

She decided to stop studying electric fish and focus her physiological efforts on coral, which were impacted by the warming of the oceans.