"Mr. Sandman" (sometimes rendered as "Mister Sandman") is a popular song written by Pat Ballard which was published in 1954 and first recorded in that year by The Chordettes. The song's lyrics convey a request to "Mr. Sandman" to "bring me a dream," the word "dream" ambiguously referring to a real significant other as well as to a sleeping dream - the traditional association with the folkloric figure, the sandman. The pronoun used to refer to the desired dream is often changed depending on the sex of the singer or group performing the song. Some time later, Ballard also rewrote the lyrics for Christmas use as "Mr. Santa". The song has an interesting music theoretical aspect, as the chord progression in the chorus follows the circle of fifths for six chords in a row.

The Chordettes recording of the song was released on the Cadence Records label whose founder, Archie Bleyer, is credited on the disc's label as "knees played by" and orchestra conductor. The piano is played by Moe Wechsler. The single reached #1 on the Billboard United States charts and #11 on the United Kingdom charts in 1954. In November 1954, The Four Aces released a version that charted even higher in the UK, reaching #9 and in the same year a version by Max Bygraves reached #16 on the UK charts. On the Cash Box magazine charts in the US, where all versions were combined, the song also reached #1.

There are numerous recorded versions of the song including versions by Chet Atkins, Mocedades, Blue Diamonds, Marvin Gaye, The Supremes, The Puppini Sisters and Blind Guardian, and it has featured in a number of TV and film soundtracks including The Simpsons, Back to the Future, Philadelphiaand several of the Halloweenfilms.

The "Mr. Santa" version has been recorded by Lenny Dee, Amy Grant, and Suzy Bogguss, among others.

In 2009, Californian Youtube based duo Pomplamoose released a free download version for their 70,000-odd subscribers. Collaborating with Ryan Lerman on acoustic guitar, the track features Jack Conte on drums & brushes, piano, keyboards, a toy piano, xylophone & accordion, with Nataly Dawn coloring the song with multi tiered vocal harmonies.

In 1978, Emmylou Harris, Dolly Parton, and Linda Ronstadt recorded a version for a planned trio album that was never completed. The song was released by Harris as a single in 1981 for which she re-recorded all three vocal parts herself as neither Parton's nor Ronstadt's record companies would allow their artists' vocals on the single. Harris also included her version on her album Evangeline.

In 1996, German power metal band Blind Guardian released a single with a cover version of "Mr. Sandman". While the song starts in a similar mood to the original, it becomes increasingly aggressive, introducing heavy metal guitars in the second verse and a double bass drum in the third.