Helmet is an American post-hardcore band formed in New York City by Page Hamilton (vocals/guitar) with Henry Bogdan (bass), Peter Mengede (guitar) and John Stanier (drums) in 1989. They were spotted by Tom Hazelmeyer and signed to his Amphetamine Reptile Records label, releasing their debut 7 inch single, Born Annoying, later that year. AmRep released their first album, Strap It On, in 1990.

Helmet was acclaimed as a thinking person's hardcore band. The members' appearance was a shock to many as they were all clean-cut - the antithesis of the heavy metal stereotype. Their music is characterized by repetitive, syncopated, staccato guitar riffs, often in odd time signatures, and almost always in a minor key with drop-D tuning. The guitar sound is heavily distorted and dissonant, with choruses that often involve guitar feedback waves. Page Hamilton has been hailed as one of the more innovative metal guitarists of the 1990s.

Before Hamilton had settled on a name for the group, Peter Mengede's then-girlfriend suggested the name "Helmut". Opting for the Anglicized spelling, Hamilton thought Helmet "sounded like a cool name for a band." Other names considered were "Cry Ruth" and "Poly Orchids".

The group rose to international stardom in 1992 after signing to Interscope Records. With the record industry hot to pick up burgeoning metal acts, Helmet was courted by a number of major labels. It is rumored that the members received in excess of $1 million at signing, along with an unprecedented amount of control over their work. Their first Interscope release, 1992's Meantime, was produced entirely by the band and was certified gold in the US by 1994. The album has sold over 1 million copies worldwide and remains Helmet's top-selling album. The group has been on the cutting edge of metal music, even helping pioneer "rap-metal" when they performed together with House of Pain for the soundtrack of the 1993 movie Judgment Night.

Helmet toured relentlessly and internal tensions rose high at times. In early 1993, guitarist Peter Mengede left on bad terms and was replaced by Rob Echeverria. After recording and touring in support of 1994's Betty, Echeverria left to join Biohazard; however, his departure was much more amicable than Mengede's. Now a three-piece, the band elected to push on and record 1997's Aftertaste without looking for another guitarist. After recording was complete, guitarist Chris Traynor (formerly of Orange 9MM) was recruited for the supporting tour. Unfortunately, the Aftertaste tour in 1997-98 would prove to be the band's last for a few years. Amid long-standing private disputes, the members decided very bitterly to call it quits. Asked about the break up, Hamilton replied, "9 years, 1600 shows, 5 albums and we found it hard to look at each other anymore."

In 2003, under the urging of Interscope Records, Hamilton re-formed Helmet, recruiting drummer John Tempesta (of Testament and White Zombie) and bringing back Chris Traynor. The trio released Size Matters in 2004 and toured with Frank Bello and then Jeremy Chatelain as touring bass-players.

In 2006 Tempesta left to join The Cult and Mike Jost replaced him as Helmet left Interscope and moved to Warcon Enterprises before releasing Monochrome. After the Warped Tour in support of the album, everyone but Hamilton left the band - seemingly on good terms. New members Kyle Stevenson (drums) and Jon Fuller (bass) have been announced as of September 2006 with a second guitarist to follow.