Dietrich A. Stephan (born August 25, 1969) is an American human geneticist and entrepreneur who works in personalized medicine.

[4] In 2003, Stephan worked at Translational Genomics Research Institute (TGen) as a Senior Investigator and founding Chairman of the Department of Neurogenomics.

Stephan crafted the business case and obtained the initial funding for the Gene Partnership Project at Children's Hospital Boston and Harvard Medical School.

In January 2007, bases on a publication from his group in Science, he co-founded Amnestix, a pharmaceutical company that focuses on the treatment of learning and memory impairment, acquired by Sygnis AG.

In 2009, together with Vern Norviel, he co-founded Aueon, Inc., a biotechnology company that invented and patented tumor sequencing and targeted therapeutic selection for cancer patients which is now emerging as the standard of care in oncology.