Apollo 440 (alternately known as Apollo Four Forty or @440) are an English band formed in Liverpool in 1990. Apollo 440 have written, recorded and produced five albums, collaborated with and produced other artists, remixed as Apollo 440 and as ambient cinematic alter-ego Stealth Sonic Orchestra, and created music for film, television, advertisements and multimedia. During their eleven years at Sony, 1993–2004, they notched up 11 Top 40 UK singles with three Top 10s, and had a chart presence worldwide.

The name comes from the Greek god Apollo and the frequency of concert pitch — the A note at 440 Hz, often denoted as "A440", and the Sequential Circuits sampler/sequencer, the Studio 440. They changed the writing of their name from Apollo 440 to Apollo Four Forty in 1996, though they switched back for their latest album.

To date Apollo's remixes number around 60 - from U2 in the early 1990s to Puff Daddy/Jimmy Page and Ennio Morricone a decade later. Apollo's version of Puretone's "Addicted To Bass" was made a lead track and became a hit in 2002. Among their Stealth Sonic Orchestra remixes are a series of Manic Street Preachers singles.

Apollo 440 were formed by the brothers Trevor and Howard Gray with fellow Liverpudlians Noko and James Gardner, although Gardner left after the recording of the first album. All members sing and add a profusion of samples, electronics, and computer-based sounds.

After relocating to the Camden area of London, Apollo 440 recorded their debut album, Millennium Fever, and released it in 1994 on their own Stealth Sonic Recordings label (distributed by Epic Records). They have successfully invaded both the record charts and the dance floor with their combination of rock, techno, and ambient.

The band had been most known for its remixes until the release of Liquid Cool in the UK. However, it was not until the success of the singles "Krupa" and "Ain't Talkin' 'bout Dub" that their own musical efforts were brought to international attention — particularly the latter single contributed greatly to pushing Apollo 440 into the spotlight.

In 2007, the band played a tribute gig to the late singer Billy Mackenzie.

Apollo 440's fifth album, The Future's What It Used To Be, became available for download on the iTunes Store from the 23rd March 2012.

Collaborators over the years have included Jeff Beck, Jean Michel Jarre, Billy Mackenzie, Ian McCulloch and Hotei.

Currently, the band resides in Islington, London, having once again moved its headquarters (affectionately labelled 'Apollo Control').