Funk metal (also known as thrash funk or punk-funk) is a fusion genre of funk rock and alternative metal which infuses heavy metal music (often thrash metal) with elements of funk and punk rock. It was prevalent in the mainstream during the late 1980s and early 1990s, as part of the alternative metal movement. The genre has been described as a “brief but extremely media-hyped stylistic fad”.

According to AllMusic, funk metal “takes the loud guitars and riffs of heavy metal and melds them to the popping bass lines and syncopated rhythms of funk”. They go on to state “funk metal evolved in the mid-’80s when alternative bands like the Red Hot Chili Peppers and Fishbone began playing the hybrid with a stronger funk underpinning than metal, although early attempts at combining the two music styles had existed as far back as 1975 when the Welsh heavy metal band Budgie released their album Bandolier. The bands that followed relied more on metal than funk, though they retained the wild bass lines.” In spite of the genre’s name, the website categorises it as a style of alternative rock rather than heavy metal music.

In his book Know Your Enemey: The Story of Rage Against the Machine, Joel Mclver wrote that funk metal is “a slightly clumsy term applied in the late eighties to any rock band whose bass player used a slapping style.” He goes on to write “The best known funk-metallers were the Red Hot Chili Peppers (who later achieved global success with a more pop-oriented approach) and Living Colour (an impossibly talented group of players who were just too far ahead of their time to keep it together for long). Other funk-metallers ranged from the credible, such as Infectious Grooves (a side-project of hardcore punks Suicidal Tendencies), to the relatively obscure, such as the Dan Reed Network.”

The self-titled 1984 debut album from Red Hot Chili Peppers has been cited as the first funk metal or punk-funk release. Faith No More, another Californian group who gained popularity in the mid-1980s, have been described as a funk metal band that also dabbled in rap-metal. Rage Against the Machine’s mix of funk and metal not only included rap, but also elements of hardcore. Certain bands not from a punk/alternative background, such as glam metal groups Bang Tango and Extreme, have also frequently incorporated funk into their musical style. Bands such as Primus and Mordred emerged from the thrash metal underground. Primus, a band that crosses many genres, has been widely described as funk metal, though bandleader/bassist Les Claypool dislikes the categorization. Claypool remarked in 1991, “We’ve been lumped in with the funk metal thing just about everywhere. I guess people just have to categorise you”. Living Colour have been named by Rolling Stone as “black funk metal pioneers.” Entertainment Weekly noted in a May 1991 article that “Despite the rise of black rockers like Living Colour, the American funk-metal scene is predominantly white.” Many reviewers often cited Living Colour as having been a band that were directly inspired by the Red Hot Chili Peppers. The vocalist of the Red Hot Chili Peppers, Anthony Kiedis, played down similarities between the two bands. He stated at the time, “Living Colour to me sounds nothing like Red Hot Chili Peppers. But I have to deal with on a daily basis: ‘Wow, Living Colour’s really biting your style. Y’ever see the guy on stage? He moves just like you.'”

The funk metal sound was most prevalent in the West Coast of the United States, particularly in the state of California, although it managed to gain some international recognition through foreign acts such as British group Scat Opera and Super Junky Monkey, an all-female funk metal/avant-garde band from Japan.

The success of Faith No More’s 1989 song “Epic” helped heighten mainstream interest in the genre around the world. Anthony Kiedis later claimed Faith No More’s singer, Mike Patton, had stolen the funk metal aesthetic he pioneered in the 1980s, specfically in “Epic” and its popular music video. He said “I watched ‘Epic’ video, and I see him jumping up and down, rapping, and it looked like I was looking in a mirror.” Since the Red Hot Chili Peppers had not yet broken outside of America, he believed European audiences would view him as being an imitator of Patton. The LA Weekly state: “Faith No More, then led by vocalist Chuck Mosley, before Patton joined the band, used to open for the similarly progressive Peppers just as the funk-metal scene was gaining momentum. By 1989, as both bands were getting exceedingly popular, they both landed European tours, with Faith No More’s scheduled to begin a few months before RHCP’s. This wasn’t an issue, until Kiedis saw the video for FNM’s ‘Epic'”. The feud continued in the late 90s and early 2000s with Patton’s other funk metal band, Mr. Bungle, who were heavily inspired by the Red Hot Chili Peppers in their early days.

The genre had reached a commercial peak by late 1991, with funk metal albums such as Blood Sugar Sex Magik (by Red Hot Chili Peppers), Sailing the Seas of Cheese (by Primus) and Mr. Bungle’s self-titled debut attaining critical acclaim from the mainstream music press. Mark Jenkins of The Washington Post claimed in a 1991 article that “much of it sounds like art rock”.

According to Steev Esquivel of the band Skinlab, the prevalance of funk metal around this time hurt the popularity of thrash metal music in the San Francisco Bay Area. He said Primus and Faith No More “came in and shut down the metal scene single handedly”, and that bands such as these attracted a large female demographic that had previously followed thrash metal.

By the latter part of the 90s, funk metal was represented by a smaller group of bands, including Incubus, Sugar Ray, Jimmie’s Chicken Shack and 311. Bands from other genres such as nu metal (Korn, Primer 55, Bloodhound Gang) and punk (Snot, Zebrahead) also incorporated elements of funk metal into their sound during the late 90s and early 2000s. Korn, who are often credited with popularizing the nu metal genre on their 1994 debut, have mentioned Faith No More and the Red Hot Chili Peppers as their two earliest influences. Mega!! Kung Fu Radio, the 1997 major label debut of Powerman 5000, showcased an aggressive form of funk metal, which the band themselves branded as “action-rock”. All subsequent releases from Powerman 5000 moved towards an industrial metal/industrial rock sound. AllMusic suggests the genre was “played-out by the end of the decade”. Influential 80s and early 90s acts such as Faith No More, Mr. Bungle and Red Hot Chili Peppers had largely abandoned the sound in favor of other styles by this point. Faith No More’s bassist Billy Gould claimed he was “sick” of the genre as early as 1992, although the band’s 1992 album Angel Dust has been described as having some funk metal characteristics. In 1995, he said: “we were perceived as a gimmick: a mixture of metal and funk and we had this pretty-boy singer. We found it really repulsive. We started getting tapes from bands who were heavy metal funk bands and they were saying we were their main influence, it was horrible. Angel Dust was a way for us to stretch our arms out and hold on to our identity, Patton cut his hair and changed how he looked.” Red Hot Chili Peppers’ 1995 album One Hot Minute was still considered to have elements of their original funk metal/punk-funk sound, however, beginning with 1999’s Californication, they began heading towards a more mainstream funk-influenced pop direction. According to The Washington Post in 1999, acts such as Korn and Limp Bizkit built on the “funk/metal/rap hybrid” of Red Hot Chili Peppers during the four year interval between One Hot Minute and Californication. However, Anthony Kiedis has stated, “I don’t think any of those conservative, ultra-aggro, rap metal bands had the funk influence or punk-rock energy that we had.”

During 2001, Alien Ant Farm released a hugely successful funk metal cover of Michael Jackson’s “Smooth Criminal”, an electro funk song. Bands from the 2000s and 2010s described as funk metal include Psychostick, Twelve Foot Ninja and Prophets of Rage (a supergroup featuring members of Cypress Hill, Public Enemy and Rage Against the Machine).

In 2016, Vice Magazine referred to funk metal as “a mostly-forgotten and occasionally-maligned genre”. Mr. Bungle guitarist Trey Spruance mentioned his fondness for the genre in a 2007 interview. When asked if he thought it would make a comeback, he stated “Fuckin’ revisionists probably won’t think its cool enough… they’ll go straight for the flannels and heroin.”