The song was written in March 1972 by 20th Century Fox songwriters Al Kasha and Joel Hirschhorn, who were asked to write the love theme for The Poseidon Adventure in one night. The finished product was called "Why Must There Be a Morning After?" but changes by the record label resulted in the song's more optimistic lyric of "there's got to be a morning after". In the end titles of the film, it is called "The Song from The Poseidon Adventure", though it would become best known by the title of the single, "The Morning After".
The song is performed in the film by the character of Nonnie, played by Carol Lynley, but is actually sung by a vocal double, Renee Armand. It appears twice, during a warm-up rehearsal and then later during the New Year's Eve party early in the film. The lyrics relate to the themes of the film, as a band of passengers survive the capsizing of the ship SS Poseidon and have to escape the sinking wreck.
When the film became a hit, Russ Regan, manager of 20th Century Records, suggested that Maureen McGovern, who had sent him a demonstration tape and was working at the time as a secretary, sing the song for the commercial release. He financed the recording with his own money and contracted her to his company. The recording was produced in Cleveland, Ohio, at Agency Recording Studios; produced by Carl Maduri and arranged by Joe Hudson. The song became a global hit.
McGovern's version was the only recording commercially available until 2010 when the complete film score, including the film versions of the songs, was released by La La Land Records.