"Nights in White Satin" is a 1967 single by The Moody Blues, written and composed by Justin Hayward and first featured as the segment "The Night" on the album Days of Future Passed. When first released in 1967, the song reached #19 on the UK Singles Chart and #103 in the United States in early 1968. It was the first significant chart entry by the team since "Go Now" and its recent lineup change, in which Denny Laine had resigned and both Hayward and John Lodge had joined.

Upon its 1972 reissue, the single hit #2 – for two weeks – on the Billboard Hot 100 (behind "I Can See Clearly Now" by Johnny Nash) and hit #1 on the Cash Box Top 100 in the United States. It earned a Gold certification for sales of over a million U. S. copies. It also hit #1 in Canada. In the wake of its American success, the song re-charted in the U. K. in late 1972 and climbed to #9. The song was re-released yet again in 1979, and charted for a third time in the U. K. – peaking at #14.

Band member Justin Hayward wrote and composed the song at age 19 in Swindon, and titled the song after a girlfriend gave him a gift of satin bedsheets. The song itself was a tale of a yearning love from afar, which leads many aficionados to term it as a tale of unrequited love endured by Hayward.

The London Festival Orchestra provided the orchestral accompaniment for the introduction, the final rendition of the chorus, and the "final lament" section, all of which were in the original album version. The "orchestral" sounds in the main body of the song were actually produced by Mike Pinder's Mellotron keyboard device, which would come to define the "Moody Blues sound."

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