"Paint Box" (or, "Paintbox" on later reissues) is a song by the psychedelic rock band Pink Floyd, written and sung by keyboardist Richard Wright. It was first released in 1967 as the B-side to the single "Apples and Oranges".

Musical features of the song include its long drum fills by Nick Mason, and a piano solo by Wright, which is panned around the stereo spectrum. Wright also doubles on tack piano in addition to the ordinary acoustic piano.

The song's lyrics begin with "Last night I had too much to drink / Sitting in a club with so many fools", and feature an ambivalent chorus: "I open the door to an empty room / Then I forget".

The song is the first of many Pink Floyd songs to prominently feature an E minor added ninth chord. This chord would become a signature aspect of their better-known material: It opens The Dark Side of the Moon with "Breathe". It is prominent in "Welcome to the Machine" from Wish You Were Here, where it alternates with a C Major seventh chord for most of the song. "Dogs" from Animals centers around the chord as played on down-tuned guitars, resulting in a concert pitch of D minor ninth. It appeared again in "Hey You" and "Vera" from The Wall. It would appear in no less than four songs from The Final Cut: "Your Possible Pasts"; "The Hero's Return"; "The Gunner's Dream"; and "The Fletcher Memorial Home".

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