"Embryo" (sometimes called "The Embryo") is a song by Pink Floyd. It was a concert staple in 1970–71, but a full band version was never released on any Pink Floyd studio album. A studio version did appear in 1970 on the rare multi-artist album Picnic – A Breath of Fresh Air. Its next appearance was in 1983 on Pink Floyd's own compilation Works. It then appeared in 2007 on A Breath of Fresh Air – A Harvest Records Anthology 1969–1974 (one of only three tracks from the original sampler album to be included in the similarly-titled anthology).

The studio version of the song, recorded in 1968, is a quiet, almost acoustic piece sung by David Gilmour lasting less than five minutes. The song ends with an organ solo and high-pitched vocal gibberish (with bassist Roger Waters having sped his voice up, much like he would later do on "Several Species of Small Furry Animals Gathered Together in a Cave and Grooving with a Pict"). This studio take has not appeared on any Pink Floyd album except Works, a US compilation. A short version, similar to the studio cut, was recorded live at a BBC session on 2 December 1968. "Embryo" was finally granted widespread release in the 2016-2017 Early Years box set. The set includes the original studio recording, the 1968 BBC live session, and other live performances from 1970 and 1971.

The earliest known instance of Embryo played live was 18 January 1970, in Croydon. It was far longer than the studio take, lasting twelve minutes. It more closely resembled the studio take in arrangement, with Gilmour playing the acoustic rhythm part on electric guitar and Wright playing the piano and organ parts on the vibraphone. It closed with a reprise of the first verse.

The next recorded instance of the song being played was 11 February 1970, in Birmingham. By then it had reached the stage at which it would remain for the rest of its existence. It lasted a minimum of around 12 minutes but the jam section was often extended and the song could last up to around 25 minutes. Wright moved from the vibraphone back to the Hammond organ, Gilmour played a distinct lead part (making the arrangement less soft and more like a rock song), and as well as a reprise added a new section of music in the middle of the song. After the second verse Roger Waters opened up the jam section with a simple bass ostinato playing the blues scale. In lieu of Roger Waters' chirping on the studio version, a tape machine from the soundboard played a recording of children playing as the band continued to jam. Near the end of the section, David Gilmour created the famous "whalesong" effect (by reversing the cables on his wah pedal). This effect would appear much more prominently and famously in "Echoes", a year later.

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