The Day After Trinity: J. Robert Oppenheimer and the Atomic Bomb) is a 1981 documentary film directed and produced by Jon H. Else in association with KTEH public television in San Jose, California.

[2] The film tells the story of J. Robert Oppenheimer (1904–1967),[3] the theoretical physicist who led the effort to build the first atomic bomb, tested in July 1945 at Trinity site in New Mexico.

The Day After Trinity was released on VHS cassette by Pyramid Home Video, and on Region 1 DVD by Image Entertainment.

[6] In July 2023,[7] after the release of Christopher Nolan's Oppenheimer, the Criterion Channel streamed The Day After Trinity for free; it was one of the service's most-streamed films during that time.

[8] The beginning of the nuclear age is not a single subject but a series of subjects that lead one to another in an unending chain reaction...That this is tacitly recognized is the most valuable aspect of The Day after Trinity: J. Robert Oppenheimer and the Atomic Bomb, Jon Else's documentary feature that opens today (January 20, 1981) at the Public Theater.