Suicidal Tendencies is an American crossover thrash band formed in 1980 in Venice, California, by vocalist Mike Muir. The band has undergone various lineup changes, with Muir as the only remaining original member. Their current lineup includes Muir, guitarists Dean Pleasants and Ben Weinman, bassist Tye Trujillo and drummer Jay Weinberg. Notable musicians who have contributed to the band's studio or live activities include guitarists Rocky George and Mike Clark; bassists Louiche Mayorga, Bob Heathcote, Robert Trujillo, Ra Díaz, Josh Paul and Stephen "Thundercat" Bruner; and drummers Amery Smith, Jimmy DeGrasso, Brooks Wackerman, David Hidalgo Jr., Thomas Pridgen, Ron Bruner, Eric Moore, Dave Lombardo, Brandon Pertzborn, Greyson Nekrutman and session musician Josh Freese.

Along with D.R.I., Corrosion of Conformity, and Stormtroopers of Death, Suicidal Tendencies is often credited as one of "the fathers of crossover thrash". They have released fourteen studio albums (four of which are composed of re-recorded or previously released material), two EPs, four split albums, four compilation albums, and two long-form videos. The band achieved its first success with their 1983 self-titled debut album; it spawned the single "Institutionalized", which was one of the first hardcore punk videos to receive substantial airplay on MTV. Suicidal Tendencies' popularity continued to grow exponentially within the next decade, and with their second studio album Join the Army (1987), which was their first to enter the Billboard 200 chart, the band was beginning to experiment with a heavy sound that helped create, develop and popularize the crossover thrash genre. Suicidal Tendencies' first three albums on the major label Epic Records — How Will I Laugh Tomorrow When I Can't Even Smile Today (1988), Controlled by Hatred/Feel Like Shit... Déjà Vu (1989) and Lights...Camera...Revolution! (1990) — were well-received in the thrash metal and heavy metal communities, with the latter two earning Suicidal Tendencies gold certifications by the RIAA. The band's sixth studio album, The Art of Rebellion (1992), became their greatest chart success, peaking at number 52 on the Billboard 200, and included three of their biggest hits "Asleep at the Wheel", "Nobody Hears" and "I'll Hate You Better". That album, along with its predecessor and its successors Still Cyco After All These Years (1993) and Suicidal for Life (1994), saw the band experiment further, with sounds and influences ranging from thrash metal to progressive and funk music.

Suicidal Tendencies disbanded in 1995 after severing ties from Epic. However, Muir (along with Clark) reformed the band a year later with a new lineup, releasing the albums Freedumb (1999) and Free Your Soul and Save My Mind (2000). Suicidal Tendencies' recorded output was minimal for the remainder of the 2000s, continuing mostly as a live band albeit occasionally performing new songs in concert and releasing them on split albums or compilation albums, including Friends & Family, Vol. 2 (2001) and Year of the Cycos (2008). The band returned to releasing new studio albums in the 2010s, starting with an album of re-recorded material, No Mercy Fool!/The Suicidal Family (2010), followed by two albums with all-new original material: 13 (2013) and World Gone Mad (2016); both albums were well-received by critics, and considered comebacks for Suicidal Tendencies. Their most recent releases are the EP Get Your Fight On! and an album featuring unreleased and re-recorded material, Still Cyco Punk After All These Years, both released in 2018. The band is currently working on new material for their fifteenth studio album.

Suicidal Tendencies was formed in 1980 as a punk band in Venice, California. The original lineup of the band consisted of Mike Muir on vocals, Mike Ball on guitar, Carlos "Egie" Egert on drums, and Mike Dunnigan on bass. After the recording of their first demo, Carlos Egert left the band and was replaced by Dunnigan's brother, Sean. Muir, at the time a student at Santa Monica College, originally only intended Suicidal Tendencies as a "party band", but as they grew in notoriety he soon found the band at the center of his life. Suicidal Tendencies had a rough start, including being voted "Worst Band/Biggest Assholes" by Flipside in 1982 but the following year were voted "Best New Band". There were many rumors of the band being involved with gangs, and their concerts were known for violence.

In their original lineup photo, which can be seen inside their self-titled debut album, drummer Amery Smith is wearing a flipped up hat and under the bill are the markings "V13", thought to be initials for Venice 13. Smith was not a member of V13 and the hat worn in the photo was borrowed from V13 member Steve Mayorga, brother of Suicidal Tendencies bassist Louiche Mayorga. Eventually another gang sprang up possibly named after the band, the Suicidal Cycos (also known as the Suicidals, Suis or Suicidal Boyz) with chapters in Venice, Long Beach, Santa Monica, Orange County, Oceanside, San Diego, and in San Antonio, Texas.

Suicidal Tendencies quickly gained a following and began performing at larger gigs. They recorded a demo in 1982 and were featured on the Slamulation compilation album on Mystic Records. The song featured was "I Saw Your Mommy", which was later featured on their self-titled debut album. The Dunnigan brothers quit after these recordings, with Mike Dunnigan later joining Tony Alva's band the Skoundrelz to be back with Mike Ball on guitar and Bela Horvath on drums. Ball stayed in the band for 2½ years before joining the Skoundrelz and was replaced by Dunnigan. Guitarist Rick Battson recorded the demo before the first album. Grant Estes learned that demo replacing him on guitar and playing on Suicidal Tendencies's first record.

In 1983, Suicidal Tendencies signed with the independent label Frontier Records and released their self-titled debut. It was described by critic Steve Huey as "Fast, furious, and funny... Mike Muir proves himself an articulate lyricist and commentator, delving into subjects like alienation, depression, and nonconformist politics with intelligence and humor." It contained the song "Institutionalized", which featured a music video that became one of the first hardcore punk videos to receive substantial MTV airplay, and greatly expanded the band's fan base. Prior to creating the "Institutionalized" video, the band appeared on an episode of the MTV program, "The Cutting Edge", which generated some criticism by fans who regarded MTV as too mainstream; criticism to which Muir responded, "I think it was the best thing that's been on MTV! It's a helluva lot better to see Suicidal Tendencies on [MTV] than it is to see Duran Duran." The song "Institutionalized" was later featured in the 1984 film Repo Man, as well as in a 1986 episode of the TV show Miami Vice which also featured a cameo appearance of the group performing in a club. Soon after the release of their debut album in 1983, Estes left the band and was replaced by Jon Nelson.

That same year was the beginning of Suicidal Tendencies's four-year recording hiatus and Mike Muir and bassist Louiche Mayorga formed the label Suicidal Records as well as the band Los Cycos. After some lineup changes the band recorded the song "It's Not Easy" written by Muir. "Welcome to Venice" was the first record to be released on Suicidal Records; the original masters were later destroyed in a fire. In 1989, Suicidal Tendencies re-recorded "It's Not Easy" for their release Controlled By Hatred/Feel Like Shit... DejaVu album. The other Los Cycos track "A Little Each Day" which never made it to the album, was re-recorded for the 1987 Suicidal Tendencies release Join the Army and again on Still Cyco After All These Years released in 1993. In 2000 it resurfaced on the FNG compilation and a fourth time on 2008's (split) album Lights...Camera...Revolution!/Still Cyco After All These Years. The band found a new label in Caroline Records in 1986.