Alice Mary Stewart, née Naish (4 October 1906 – 23 June 2002) was a British physician and epidemiologist specialising in social medicine and the effects of radiation on health.

Her study of radiation-induced illness among workers at the Hanford plutonium production plant, Washington, is frequently cited by those who seek to demonstrate that even very low doses of radiation cause substantial hazard.

In 1950 she succeeded as head of the unit, but to her disappointment she was not granted the title of "professor", as awarded to her predecessor, because by then the post was considered not to be of great importance.

[4] Working with Professor Thomas Mancuso of the University of Pittsburgh she examined the sickness records of employees in the Hanford plutonium production plant, Washington state, and found a far higher incidence of radiation-induced ill health than was noted in official studies.

[10] Stewart eventually gained her coveted title of "professor" through her appointment as a professorial fellow of Lady Margaret Hall, Oxford.