There are two bands with such name at least.
1. 'Okay' is a band from Fremont, California and is the side project of Dilute's Marty Anderson, who is the only fully permanent member of the band.
2. A Western German, Frankfrurt am Main originated four guys' band, sometimes falsely spelled as O.K. It was formed in 1986 (?), playing in Synth-Pop, Eurodance, New Beat, Euro House (later) style. 1st their song and single OKAY! they released in 1987, that had reached #2 of the German music charts in 1988 and #1 of the Austrian charts. They received 2 gold records for this single.
* Marcus Gabler (aka Marc Gable, m-cee): Vocals, keyboards, tapes, mixing.
* Nikki: Drums, backing vocals
* Robin Otis: Bass, backing vocals
* Christian Berg: Keyboards, backing vocals
* 1987 Okay! (Single)
* 1988 E-D-U-C-A-T-I-O-N (Single)
* 1989 The Wild, Wild, Western (Single)
* 1989 Bang (Album, CBS)
* 1990 220.127.116.11. Une grande Affaire (Single), featuring Valerie Vannobel
* 1991 World Of Illusion (Single)
* Official band website (http://www.okayband.com/)
* Okay in Discogs (http://www.discogs.com/artist/O.K)