Hazel Reid O'Leary (born May 17, 1937) is an American lawyer, politician, and university administrator who served as the 7th United States secretary of energy from 1993 to 1997.

O'Leary worked as a prosecutor in New Jersey and then in a private consulting/accounting firm before joining the Carter administration in the newly created Department of Energy.

During her tenure, she declassified documents detailing how the United States had conducted secret testing on the effects of radiation on unsuspecting American citizens.

[3] From 1989 to 1993, O'Leary worked as an executive vice president of the Northern States Power Company, a Minnesota-based public utility.

[8][9] In a press conference on December 21, 1992, held in Little Rock, Arkansas, then President-elect Bill Clinton announced his intention to nominate O'Leary as secretary of energy.

[17][7] While reducing the size of the department overall, O'Leary shifted resources toward efficient and renewable energy sources,[18] a priority of the Clinton administration.

[7] In this position, O'Leary won praise for declassifying old Department of Energy documents,[17][19] including Cold War-era records that showed the U.S. government had used American citizens as guinea pigs in human radiation experiments, as had long been rumored.

[17] Clinton issued Executive Order 12891, which created the Advisory Committee on Human Radiation Experiments (ACHRE) to prevent such abuses of power.

[17] Early in her tenure as secretary, O'Leary met with whistle-blowers who said they faced harassment for raising legitimate health and safety issues within the DOE.

The DOE allocated $43,500 to a Washington firm to identify unfriendly media outlets, which White House Press Secretary Michael D. McCurry called "unacceptable.

"[17] O'Leary claimed the allocation was made without her direct knowledge and defended the research as an attempt to study the efficacy of the department's messaging.

[26] In August of that year, Attorney General Janet Reno reviewed Chung's allegations to decide whether to appoint a special prosecutor to investigate O'Leary.

[26] Some observers, including a lawyer for the Government Accountability Project, saw some fault in O'Leary's conduct but also saw racism and sexism in the way she was treated.

[24] On July 13, 2004, O'Leary was selected and began work as president of her undergraduate alma mater, Fisk University, a historically black college in Nashville, Tennessee.

[36] Under O'Leary's leadership, Fisk went to court in December 2005 seeking a ruling that it could sell a portion of the university's Alfred Stieglitz Collection.

[38] Ultimately, after seven years of legal battles, the school was able to reach a deal with Crystal Bridges Museum of American Art in Arkansas to share the collection.

She also served on the board of directors for nonprofit organizations such as the Nashville Alliance for Public Education, the Nashville Business Community for the Arts, and the Arms Control Association, and as a trustee on boards of the World Wildlife Fund, Morehouse College, and The Andrew Young Center of International Development.