Indie rock is a subgenre of rock music that originated in the United Kingdom, United States and New Zealand in the early to mid-1980s. Although the term was originally used to describe rock music released through independent record labels, by the 1990s it became more widely associated with the music such bands produced.

The sound of indie rock has its origins in the UK DIY music of the Buzzcocks, Desperate Bicycles and Television Personalities and the New Zealand Dunedin sound of the Chills, Tall Dwarfs, the Clean and the Verlaines, alongside Australia's the Go-Betweens and early 1980s college rock radio stations who would frequently play jangle pop bands like the Smiths and R.E.M. The genre solidified itself during the mid–1980s with NME's C86 cassette in the United Kingdom and the underground success of Sonic Youth, Dinosaur Jr. and Unrest in the United States. During the 1990s, indie rock bands like Sonic Youth, the Pixies and Radiohead all released albums on major labels and subgenres like slowcore, Midwest emo, slacker rock and space rock began. By this time, "indie" had evolved to refer to bands whose music was released on independent record labels, in addition to the record labels themselves. As the decade progressed many individual local scenes developed their own distinct takes on the genre: baggy in Manchester; grebo in Stourbridge and Leicester; and shoegaze in London and the Thames Valley.

During the 1990s, the mainstream success of grunge and Britpop, two movements influenced by indie rock, brought increased attention to the genre and saw record labels use their independent status as a marketing tactic. This led to a split within indie rock: one side conforming to mainstream radio; the other becoming increasingly experimental. By this point, "indie rock" referred to the musical style rather than ties to the independent music scene. In the 2000s, indie rock reentered the mainstream through the garage rock and post-punk revival and the influence of the Strokes, the White Stripes and the Libertines. This success was exacerbated in the middle of the decade by Bloc Party, Arctic Monkeys and the Killers, while indie rock further proliferated into the 2000s blog rock era and the British landfill indie movement, as well as the indie sleaze aesthetic.

Lately we've been hearing the tag "'90s indie rock" used to describe bands ranging from Waxahatchee to Speedy Ortiz to Yuck, and while our brain immediately turns a switch that associates the phrase with "sounds like Pavement", '90s indie rock was really as eclectic and undefinable as, well, contemporary indie rock.

The terms "independent record label" or "independent music" were originally used in the 1930s to 1950s for American artists associated with jazz, rhythm and blues and early rock and roll, who were predominantly Black musicians initially sidelined by major labels, therefore relied on independent distribution to release their work.

By the early 1980s, the earliest known use of the term "indie rock" was made in an article of Billboard magazine, titled "Despite Hard Times, Indie Rock Labels Survive" on 15 January 1983 by writer Roman Kozak, in which he used a short-hand for the term "independent rock", to describe a growing trend of successful independent record labels in New York that primarily focused on the emerging alternative rock music scene. Indie rock originally described a style of alternative rock that was associated with small and relatively low-budget independent labels a do-it-yourself attitude. Drawing influences from punk, psychedelia and post-punk. Although record deals were later often struck with major corporate companies, "indie rock" became more closely associated with a specific style of rock music rather than its mode of distribution.

Indie, in the beginning, was simply short for "independent" – the term was first applied to a bunch of British bands operating through independent record labels in the 1980s, most notably The Smiths. But indie-coded bands quickly became very, very popular. Defining indie as something commercially niche then made little sense, especially in the 2000s, when indie bands competed with rappers and pop stars for the top chart positions. So what are we left with? A songwriting sensibility that's a little weirder than down-the-line rock. Guitar work that often (but not always) tends towards the sharp and angular. A lot of blazers about too, but indie bands like to break rules.

AllMusic identifies indie rock as including a number of "varying musical approaches [not] compatible with mainstream tastes". Linked by an ethos more than a musical approach, the indie rock movement encompassed a wide range of styles, from hard-edged, grunge-influenced bands, through do-it-yourself experimental bands like Pavement, to punk-folk singers such as Ani DiFranco. In his book DIY Style: Fashion, Music and Global Digital Cultures, Brent Luvaas described the genre as rooted in nostalgia, citing the influence of garage rock and psychedelic rock of the 1960s in progenitors the Stone Roses and the Smiths, in addition to a lyrical preoccupation with literature.