Mary Lou McMaster is an American oncologist and clinical trialist who researches familial cancer genetics.

She is a senior clinical trial specialist at the National Cancer Institute and a captain in the United States Public Health Service Commissioned Corps.

[1] She completed residency training in internal medicine and a fellowship in medical oncology at Vanderbilt University.

[1] Following a postdoctoral fellowship in cellular biology at the UNC Lineberger Comprehensive Cancer Center, she came to the National Institutes of Health (NIH), where she completed training in clinical medical genetics.

[1] McMaster was promoted to staff clinician in 2002, and transferred to the clinical genetics branch (CGB) in 2016.