Helloween is a German power/speed metal band founded in the early 1980s by members of Iron Fist and Powerfool.

Helloween is known as one of the pioneering power metal bands. The original line-up featured Kai Hansen (Vocals/Guitars), Michael Weikath (Guitars), Markus Grosskopf (Bass) and Ingo Schwichtenberg (Drums).

In 1984 the band had signed a deal with Noise Records (see 1984 in music) and recorded two songs for a Noise compilation record called Death Metal with bands Hellhammer, Running Wild and Dark Avenger. The two tracks were "Oernst Of Life" by Weikath, and Hansen's "Metal Invaders" which later on was featured in a faster version on the band's first full-length album.

In 1989 the band released a live album called Live In The UK, featuring live material from their 1988 European tour, entitled "Keepers Live" in Japan and "I Want Out Live" in the U.S. The remaining members continued on, but ran into label problems with Noise, and, after litigation which kept them from touring and releasing new material, were eventually released from their contract.

A new album would not appear until 1991 when, after several rumors about the band breaking up, they released the comically entitled Pink Bubbles Go Ape for their new record company, EMI. Helloween then started recording for the upcoming studio album to be released on October 23, 2007. This upcoming album has a tentative worked title of "Gambling with the Devil".

Helloween will team up with Kai Hansen's current band Gamma Ray for the upcoming world tour, entitled Hellish Rock 2007/2008, that starts in early November of 2007. Helloween will be headlining and Gamma Ray are labeled to be the "very special guest" with some shows along fellow German "guest" Axxis.