"Tell Me When" is a song by English synth-pop band the Human League, released in December 1994 by East West Records as the first single from their seventh album, Octopus (1995).

Written jointly by lead singer Philip Oakey and Paul C. Beckett, the song was produced by Ian Stanley (formerly of Tears for Fears).

The song was originally written for the act "Fast Arithmetic" (Oakey–Beckett), a side project in development within the Human League environment.

[3] Released in a variety of vinyl and CD single formats, these variously included remixes of "Tell Me When" by contemporary electronic acts Utah Saints, Development Corporation and Red Jerry, a non-album B-side ("The Bus to Crookes"), and a track from the band's recent collaboration with Yellow Magic Orchestra.

It received considerable radio promotion in advance of its late 1994 UK release, hitting the airwaves at a time when many people started to get Christmas song fatigue.

[6] Capital 95.8 head of music Richard Park welcomed the single, saying "the marketplace is just ready for a fresh dose of the Human League".

"[10] David Bauder of Associated Press called the song "splendid", and noted that it is a "shimmering melody, with Kraftwerk-like synthesizers and Phil Oakey's arch voice sweetened by his two female colleagues.

[11] Also Larry Flick from Billboard was favourable, writing, "British synth-pop act that enjoyed a high profile during the '80s returns with a percolating swinger, which harkens back to its now-classic hits, 'Don't You Want Me' and 'Fascination'.

[14] Jennifer Nine from Melody Maker viewed it as "a brightly hopeful, wafer-thin compendium of standard League traits, including that pocket calculator-powered "funky" breakdown.

Anyway, the return of the Sheffield synth band in the premier division of pop creates an enormous buzz in radio land.

[20] Another NME editor, Paul Moody, viewed it as "sublimely clumsy" with "this killer Human League chorus all over it, the sort that rings around your brain like a nursery rhyme from Mars.

[24] David Sinclair of The Times commented, "All the familiar components are here join-the-dots tune, danceable synth-pop arrangement, catchy bubblegum chorus but the result sounds disconcertingly like the Human League by numbers.