The assistant secretary for health (ASH) is a senior U.S. government official within the United States Department of Health and Human Services (HHS). The position is a statutory office and the holder of the office serves as the United States Secretary of Health and Human Services's primary advisor on matters involving the nation's public health. The assistant secretary oversees all matters pertaining to the United States Public Health Service (PHS), the main division of the Department of Health and Human Services, for the secretary and provides strategic and policy direction. The Public Health Service comprises almost all of the agency divisions of the Department of Health and Human Services including the United States Public Health Service Commissioned Corps, one of the eight federal uniformed services, comprising more than 6,500 uniformed health professionals who serve with the Department of Health and Human Services, or are assigned to work within other federal agencies, including the United States Armed Forces.

The United States secretary of health and human services is the head of the United States Department of Health and Human Services, and serves as the principal advisor to the president of the United States on all health matters. The secretary is a member of the United States Cabinet. The office was formerly Secretary of Health, Education, and Welfare. In 1980, the Department of Health, Education, and Welfare was renamed the Department of Health and Human Services, and its education functions and Rehabilitation Services Administration were transferred to the new United States Department of Education. Patricia Roberts Harris headed the department before and after it was renamed.