James Ostermann Mason was the United States assistant secretary for health (ASH) from 1989 to 1993 and the acting surgeon general of the United States from 1989 to 1990. As the ASH he was also a former four-star admiral in the United States Public Health Service Commissioned Corps. He was also a director of the Centers for Disease Control and Prevention and a general authority of The Church of Jesus Christ of Latter-day Saints.

Born in Salt Lake City, Utah, Mason earned BA and MD degrees from the University of Utah and a master's degree and a PhD of Public Health from Harvard University. He was the first managing director of the LDS Church's Unified Welfare Services, directing the Church's hospital system. He served as the executive director of the Utah Department of Health until 1983, when he was named director of the Center for Disease Control and Prevention (CDC) in Atlanta, Georgia; Mason held the directorship of the CDC until 1990. In 1989, the US Senate confirmed Mason as assistant secretary for health, which made him head of the United States Public Health Service and acting surgeon general. He later served as the American delegate to the World Health Organization. In 1994, he was appointed by the LDS Church as a general authority, serving in the Second Quorum of the Seventy until 2000.

He is currently a member of the board of trustees of Evergreen International, a Utah-based non-profit organization that seeks to assist Latter-day Saints and other Christians who wish to diminish same-sex attraction and homosexual behavior.