Garside was born on 8 July 1968 in Buckrose, East Riding of Yorkshire, England, the first of two daughters. Garside spent her early years in Salisbury, Wiltshire, though her family relocated frequently as her father was in the British Army; he also had a musical background, having played in local bands in London. When she was 11 years old, Garside’s father took the family to live aboard a 32-foot (9.8 m) yacht, and they sailed the world for four years. Garside has said that spending her formative years living on the sea gave her a “different perspective on things”:

Garside formed Daisy Chainsaw in 1989 after responding to an advert in a newspaper by guitarist Crispin Gray. Bassist Richard Adams joined the band, along with Canadian drummer Vince Johnson. The group quickly became well known for their wild live performances, featuring Garside drilling doll heads onstage and drinking juice out of baby bottles. The band’s raucous concerts would sometimes result in Garside performing self-mutilation onstage. Russell Senior, guitarist of Pulp, recalled that at one 1989 concert in London, Garside wrapped the microphone cord so tightly around her neck onstage that she lost consciousness, and the show had to be ended early. Garside’s look was described as a “Gothic street urchin image, complete with dead flowers meshed into her dreadlocked hair”. In a review of one of the band’s concerts in 1991, an unnamed journalist for Bust magazine wrote: “KatieJane Garside is either in drastic need of psychiatric help or she deserves an Oscar for best actress.”

The band toured the United Kingdom with Hole and Mudhoney to promote the album prior to its release, and Garside drew comparisons from British press to Hole’s frontwoman Courtney Love. Love allegedly cited Garside as one of the “first true riot grrls” in 1991 and admitted to borrowing heavily from Garside’s aesthetic. Garside never associated herself with the movement, which was based in the Pacific Northwest of the United States.

The band released Eleventeen in 1992, which would be their only full-length album before Garside left the band in 1993. The album spawned “Love Your Money”, which was the band’s most popular single; they performed the song live on British television show The Word in 1992. “Love Your Money” reached number 26 in the UK Singles Chart in February 1992.

After Garside left Daisy Chainsaw, she disappeared from the public eye and music scene, going into seclusion, residing in the Lake District. A self-described recluse, Garside later commented that “I could be anywhere, really, and it wouldn’t make a lot of difference, so I don’t know necessarily that much about the country that I was born in and that I’ve lived in.” Due to her manic onstage histrionics and bizarre behaviour in interviews, rumours circulated that Garside had succumbed to mental illness. In later years, she admitted that she had been suffering a nervous breakdown at the time. She lived in the historical Rigg Beck, a notorious retreat for artists and bohemians. In spite of the rumours of purported seclusion, Garside was given a credit in the liner notes of the 1993 Frostbite album, Second Coming. She also collaborated with the industrial band Test Department in 1995 on their album Totality.

Garside had no intentions of returning to music until the late 1990s when former guitarist Crisipin Gray contacted her; in 1999, they formed Queenadreena and released four studio albums: Taxidermy (2000), Drink Me (2002), The Butcher and the Butterfly (2005), and Djin. Some time between 1999 and 2002, during the early stages of Queenadreena, Garside resided in Wales for a brief period.

Garside’s solo work of this time includes a collection of home recordings called Lalleshwari/Lullabies in a Glasswilderness released in 2006. Complementing this release was a collection of short films made by KatieJane. Garside also collaborated with artist Daniel Schaffer, co-creating the comic books Indigo Vertigo and Lesions in the Brain.

After recording Live at the ICA, which featured a live 2005 performance at the Institute of Contemporary Arts, the band released two more albums, Ride a Cockhorse, which featured unreleased 4-track demos, and Djin, which was their final studio release before disbanding around 2009. In 2007, Garside exhibited a collection of photographs and artwork at the Woom Gallery in Birmingham, titled Darling, they’ve found the body.

In 2007, shortly before the release of Queenadreena’s final album Djin, Garside released her first collaboration with guitarist Chris Whittingham, titled The Ventriloquist, under the band name Ruby Throat. Garside met Whittingham while he was busking at a train platform on London Underground, and asked him to collaborate. In contrast to Queenadreena’s metal and noise rock style, Ruby Throat is a more ethereal, vocal based project primarily featuring acoustic guitar. The album was well-received, and critics drew comparisons to the work of PJ Harvey and Mazzy Star.

The duo released a Tour EP in 2009, featuring handmade artwork, followed by their second record, Out of a Black Cloud Came a Bird (2009). In 2012, they released their third album, O’ Doubt O’ Stars, which featured a limited edition packaging with a book of lithographs and Garside’s art, as well as handwritten lyrics. As of 2012, she and her partner Whittingham resided on a ketch named Iona, along with their two children, then aged 10 years and 10 months. The boat was damaged in a storm in St. Mawes, Cornwall in June 2012; they made repairs in Falmouth and left England shortly afterwards with the intention to sail around the world.

According to their Facebook page, the band began working on a new album in the beginning of 2013. In 2014 a new song, “Secret Fires”, was released on the third Jeffrey Lee Pierce Sessions compilation Axels & Sockets. It was announced on August 1, 2014 that Ruby Throat’s fourth album will be called Baby Darling Taporo.

In November 2016, Garside announced the forthcoming release of a limited edition book of 34 poems entitled A whispering frayed edge. In November 2017, Ruby Throat released their fourth studio album, Baby Darling Taporo. Garside granted an extensive interview to Vice in October 2018, during which she divulged that she and Whittingham still resided on Iona with their children, and that they had recently completed an extensive sailing trip across the world.

In 2017, a book profiling KatieJane Garside’s career was released entitled Under a Floorboard World: The Career of Katie Jane Garside. It was released via Breakbeat Books, which is the publishing name of independent author Charlie Bramley. The book “provides a long overdue exploration into the career of Garside, offering rich analysis and original insight”. It also features an original interview with Garside, undertaken during the writing period.

In April 2020, Garside and Whittingham released a full-length album, Geiger Counter, under a new musical project named Liar, Flower.