Doctor Atomic is an opera by the contemporary American composer John Adams, with libretto by Peter Sellars. It premiered at the San Francisco Opera on October 1, 2005. The work focuses on the great stress and anxiety experienced by those at Los Alamos while the test of the first atomic bomb (the "Trinity" test) was being prepared. In 2007, a documentary was made about the creation of the opera, titled Wonders Are Many.

The first act takes place about a month before the bomb is to be tested, and the second act is set in the early morning of July 16, 1945 (the day of the test). During the second act, time frequently slows down for the characters and then snaps back into reality. The opera ends in the final, prolonged moment before the bomb is detonated. Although the original commission for the opera suggested that U.S. physicist J. Robert Oppenheimer, the "father of the atomic bomb," be fashioned as a 20th-century Doctor Faustus, Adams and Sellars deliberately attempted to avoid this characterization. Alice Goodman worked for two years with Adams on the project before leaving, objecting to the characterization of Edward Teller, as dictated by the original commission.

The work centers on key players in the Manhattan Project, especially Robert Oppenheimer, General Leslie Groves, and also features Kitty Oppenheimer, Robert's wife, and her anxiety over her husband's project. Sellars adapted the libretto from primary historical sources.

Doctor Atomic is similar in style to previous Adams operas Nixon in China and The Death of Klinghoffer, both of which explored the characters and personalities that were involved in historical incidents, rather than a re-enactment of the events themselves.