(born Chaim Witz; August 25, 1949) is an Israeli American rock bassist, singer, songwriter, musician, actor, and businessman. Known as "The Demon," he is the bassist/vocalist of Kiss, a hard rock band he co-founded in the early 1970s.
Simmons was ranked number 12 in Roadrunner's list of 50 Best Frontmen in Metal History.
Chaim Witz (later Gene Simmons) was born in Tirat Carmel, Haifa, Israel in 1949. The family emigrated to Jackson Heights, Queens in New York City when he was eight years old. His mother Flóra Klein (was born in Jánd, Hungary). The German name Klein (means: small) translates to Hungarian as Kiss, that gave the rock band's name. Florence and her brother, Larry Klein, were the only members of the family to survive the Holocaust. His father, Feri Witz, also Hungarian-born remained in Israel. Simmons says the family was "dirt poor," scraping by on bread and milk. In the United States, Simmons changed his name to Eugene Klein (later Gene Klein), adopting his mother's maiden name. He attended Yeshiva Torah Vodaath in Williamsburg, Brooklyn as a child, from 7 a.m. to 9:30 p.m.  
He became a science fiction fan and published several science fiction fanzines, among them Sirruish, Id, Cosmos (which eventually merged with Stilletto to become Cosmos-Stilletto and then Faun), Tinderbox, Sci-Fi Showcase, Mantis and Adventure. He also contributed to other fanzines, among them BeABohema.
Simmons, who never married, lives in Beverly Hills, California with longtime partner, former Playboy Playmate and actress Shannon Tweed. They have two children: a son, Nick (born January 22, 1989), and a daughter, Sophie, (born July 7, 1992). He formerly had live-in relationships with Cher and Diana Ross. Simmons speaks English, Spanish, Hungarian and Hebrew.
Simmons became involved with his first band, Lynx, then renamed The Missing Links, when he was a teenager. Eventually, he disbanded The Missing Links to form The Long Island Sounds, the name being a play on words relating to the estuary separating Long Island from Westchester County, New York, Connecticut and Rhode Island. While he played in these bands, he kept up odd jobs on the side to make more money, including trading used comic books. Simmons attended Sullivan County Community College in Loch Sheldrake, New York. He then joined a new band, Bullfrog Bheer, and the band recorded a demo, "Leeta"; this was later included on the Kiss box set.
Simmons formed the rock band Wicked Lester in the early 1970s with Stanley Harvey Eisen (now known as Paul Stanley) and recorded one album, which was never released. Dissatisfied with Wicked Lester's sound and look, Simmons and Stanley attempted to fire their band members; they were met with resistance, and they quit Wicked Lester, walking away from their record deal with Epic Records. They decided to form the ultimate rock band, and started looking for a drummer. Simmons and Stanley found an ad placed by Peter Criscoula, known as Peter Criss, who was playing clubs in Brooklyn at the time; they joined and started out as a trio. Paul Frehley, better known as Ace Frehley, responded to an ad they put in The Village Voice for a lead guitar player, and soon joined them. Kiss released its self-titled debut album in February 1974. Stanley quickly took on the role of lead performer on stage, while Simmons became the driving force behind what became an extensive Kiss merchandising franchise. The eye section of his "Demon" makeup with KISS came from the wing design of comic book character Black Bolt.
In 1983, while Kiss' fame was waning, the members took off their trademark make-up and enjoyed a resurgence in popularity that continued into the 1990s. The band hosted their own fan conventions throughout 1995, and fan feedback about the original Kiss members reunion influenced the highly successful 1996–1997 Alive Worldwide reunion tour. In 1998, the band released Psycho Circus, the first album in almost 20 years by the original line-up. Since then, the original line-up has once again dissolved, with Tommy Thayer replacing Ace Frehley on lead guitar and Eric Singer (who performed with Kiss from 1992 up through 1996) replacing Peter Criss on drums.
Gene Simmons has used various bass guitars during his career including:
He uses Ampeg SVT CL Series amps with 8x10 cabinets. In 2010 Gene Simmons collaborated with Cort Guitars to make a his own signature bass line called the GS-AXE-2.
Simmons has been the creative force behind such television projects as:
On March 9, 2011, Simmons and Kiss co-founder Paul Stanley and E! Entertainment announced that they have finalized a production and development deal to create an as-yet-untitled comedic half-hour kids' television series.
In 2011, Simmons was presented the key to the city in Dallas, Texas and a street, Gene Simmons Boulevard, was named for him.
In March 2011, Simmons had a homecoming visit to Israel where he was born. He described the trip as a "life changing experience". He talked how he still feels Israeli - "I'm Israeli. I'm a stranger in America. I'm an outsider".  Gene recently met his half brother Kobi, and sisters Sharon, Eugenia and Drora while in Israel.  Simmons has plans to bring his band, KISS to Israel.  He has always said that he is an ardent supporter of Israel.  At a press conference in Israel, he spoke both Hebrew and English.
|1978||Kiss Meets the Phantom of the Park||The Demon||Peter Criss, Ace Frehley, Paul Stanley||TV movie|
|1984||Runaway||Dr. Charles Luther|
|1986||Trick or Treat||Nuke (radio DJ)||Ozzy Osbourne also appeared|
|1986||Never Too Young to Die||Carruthers / Velvet Von Ragner|
|1987||Wanted: Dead or Alive||Malak Al Rahim|
|1988||The Decline of Western Civilization Part II: The Metal Years||Himself||Paul Stanley||Documentary|
|1999||Detroit Rock City||Himself||Peter Criss, Ace Frehley, Paul Stanley||Simmons also produced|
|2002||The New Guy||Reverend|
|2002||Wish You Were Dead||Vinny|
|2008||Detroit Metal City||Jack lll Dark||Japanese movie|
|2010||Rush: Beyond the Lighted Stage||Himself||Documentary|
|1974||The Mike Douglas Show||June 11, 1974||Himself||Peter Criss, Ace Frehley, Paul Stanley||Kiss' first national television appearance, performed "Firehouse"|
|1976||The Paul Lynde Halloween Special||October 29, 1976||Himself||Peter Criss, Ace Frehley, Paul Stanley||The band performed "Detroit Rock City" and "King of the Night Time World", Peter Criss performed "Beth"|
|1985||Miami Vice||"Prodigal Son"||Newton Blade|
|1997||Action League Now!||"Rock-A-Big-Baby"||Toy version of himself||Peter Criss, Ace Frehley, Paul Stanley||Performed "Rock and Roll All Nite"|
|1998||MADtv||October 31, 1998 (#406)||Himself||Peter Criss, Ace Frehley, Paul Stanley.||Halloween special; performed in five sketches|
|2001||Family Guy||"A Very Special Family Guy Freakin' Christmas"||Animated version of himself||Peter Criss, Ace Frehley, Paul Stanley|
|2001||Who Wants To Be a Millionaire?||May 27, 2001||Himself||Won $500,000 for a charity|
|2001||The Daily Show with Jon Stewart||June 12, 2001||Himself||Almost licked Jon Stewart's face in response to Jon being unable to explain the difference between pleasure and joy to a man with a 'twelve-inch tongue'|
|2002||Family Guy||"Road to Europe"||Animated version of himself||Peter Criss, Ace Frehley, Paul Stanley|
|2002||The Tonight Show with Jay Leno||September 6, 2002||Himself|
|2003||King of the Hill||"Reborn to Be Wild"||Jessie|
|2004||Third Watch||"Higher Calling"||Donald Mann|
|2004||Third Watch||"Monsters"||Donald Mann|
|2004||Third Watch||"More Monsters"||Donald Mann|
|2005||American Idol||"Auditions: New Orleans"||Himself- guest judge|
|2005||Family Guy||"Don't Make Me Over"||Animated version of himself/ Prisoner #3|
|2005||Mind of Mencia||Episode #1.7||Himself|
|2006||The View||August 1, 2006||Himself||2006||Gene Simmons Family Jewels|
|2007||SpongeBob SquarePants||"The Battle of Bikini Bottom"||Sea Monster|
|2007||Shrink Rap||"Gene Simmons"||Himself||UK's More4 show|
|2008||Entertainment Tonight||January 2, 2008||Himself|
|2008||Jimmy Kimmel Live!||January 18, 2008||Himself|
|2008||Rachael Ray||March 11, 2008||Himself|
|2008||Criss Angel Mindfreak||"Mindfreaking with the Stars"||Himself|
|2008||Ugly Betty||"The Kids Are Alright"||Himself|
|2008||Ugly Betty||"A Thousand Words by Friday"||Himself|
|2008||Are You Smarter Than a 5th Grader?||Episode #3.9||Himself||Won $500,000 for the Elizabeth Glaser Pediatric AIDS Foundation charity|
|2008||The Celebrity Apprentice||First three episodes||Himself||Fired in the third episode|
|2008||Jingles||Celebrity judge||Mark Burnett reality show|
|2009||Glenn Martin DDS||Glenn Gary, Glenn Martin||himself||no band mates were involved|
|2009||American Idol||Season Finale||Himself||Eric Singer, Tommy Thayer, Paul Stanley||Performed medley of 3 songs with contestant Adam Lambert|
|2009||The Fairly OddParents||"Wishology – Part 1: The Big Beginning"||Animated version of himself||Eric Singer, Tommy Thayer, Paul Stanley|
|2010||I Get That a Lot||Episode 2||As Himself||No Band Mates Associated||Simmons appeared as a psychic working at the Mystic Journey Bookstore in Venice, California|
|2010||Extreme Makeover: Home Edition||Episode 160||As Himself||No Kiss Band Mates Associated||The band Kiss made a personal appearance during the Wagstaff family's vacation in Disneyland and honored them as special guests at one of their concerts. Kiss also made a personal appearance at a local school where a donation of new musical instruments was made in the Wagstaff family's name.|
|2010||I'm in a Rock 'n' Roll Band!||Episode 1 And 5||As Himself||None||Discussing the requirements of being in a rock band.|
|2011||Castle||To Love and Die in LA||As Himself||None|
Gene Simmons is a playable character in Tony Hawk's Underground, unlocked when completing the story mode on Normal difficulty, and also appears with his Kiss bandmates in the Hotter Than Hell level to play one of three songs upon collecting the four K-I-S-S letters.
Gene Simmons' Kiss character, The Demon, is a playable character in Kiss: Psycho Circus: The Nightmare Child.
Simmons also has a large role in the 2010 music video game Guitar Hero: Warriors of Rock. In addition to narrating the main storyline and doing advertising for the game, the Kiss song "Love Gun" is playable.
In 2002, Simmons launched Gene Simmons' Tongue, a men's lifestyle magazine. The magazine lasted five issues before being discontinued