"Hallo Spaceboy" is a song by David Bowie from his 1995 album Outside. The track was re-recorded the following year, and issued as a single, featuring Pet Shop Boys as guest vocalists. Bowie and Brian Eno co-wrote the original album version of the song.

Bowie wrote the song in mostly-improvised sessions with his band in 1995, and intentionally wrote it with a Nine Inch Nails-like vibe. Of the track, Bowie said "I adore that track. In my mind, it was like Jim Morrison meets industrial. When I heard it back, I thought, 'Fuck me. It's like metal Doors.' It's an extraordinary sound."

The commercial (i.e. non-promo) version of the single featured a remix by Pet Shop Boys as the lead track, not the original album version. In contrast to the original, the single remix was far more disco-oriented and featured additional lyrics sung by Neil Tennant. The introduction was sampled from the opener to Outside, "Leon Takes Us Outside". Bowie initially expressed reservation about the additions, which referenced and "cut-up" the lyrics to "Space Oddity," but later agreed that they worked well. Bowie and Pet Shop Boys performed a live version of the remixed song at the Brit Awards in February 1996.

The three remixes by Dave Ball (known as the instrumentalist of Soft Cell) and Ingo Vauk are based on the Pet Shop Boys Remix, but only Double Click Mix uses Neil Tennant's vocals. Instrumental is an instrumental version of Double Click Mix.

Except the single mix, all remixes were initially released only on promo 12" singles. In 2004 they were included on the bonus disc of the re-released Outside album.

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