Radwimps (ラッドウインプス, Raddo'uinpusu; stylized as RADWIMPS) is a Japanese rock band who debuted independently in 2003 and signed with Toshiba EMI's Virgin Records label in 2005. The band's name, Radwimps, was formed from two English slang terms, "rad" and "wimp". According to the band, the coined word had several meanings, including "excellent weakling" and "superlative coward".

Radwimps achieved commercial success in 2006 with their album Radwimps 4: Okazu no Gohan and are best known for their later singles "Order Made" (2008) and "Dada" (2011), both of which hit number one on the Oricon Singles Chart. They have also gained recognition for providing the soundtracks to the anime films Your Name (2016), Weathering with You (2019), and Suzume (2022), all three by Makoto Shinkai.

Radwimps formed in 2001 in Kanagawa, Japan during their first year of high school. The five original members had been friends since middle school. Lead vocalist Yojiro Noda first became interested in music after hearing Oasis in middle school, when he would try to remember the guitar chords and sing to Oasis songs.

The band's activities were initially centred on Yokohama, and their first performance took place on BB Street in Kannai district on 5 February 2002. At this point, guitarist Akira Kuwahara dropped out of high school in order to focus on the band. In September and August 2002, Radwimps partook in the Yokohama High School Music Festival and eventually won the grand prize for the competition with the song "Moshi mo". "Moshi mo" was released as the band's debut single in May 2003, with 10,000 copies pressed and sold for 100 yen each. Following this single, Radwimps toured the Yokohama area, including a performance as the sole act at Yokohama's Club 24West. The band released their debut album, Radwimps, in July through independent label Newtraxx, featuring songs they wrote in middle school. The following August, after a guest appearance at the Yokohama High School Music Festival, the band went on hiatus for Noda and other members to focus on their school exams.

Radwimps returned from hiatus in March 2004, though Kei Asō, Yūsuke Saiki, and Akio Shibafumi did not rejoin the group. To replace the musicians, the band added acquaintances, such as drummer Satoshi Yamaguchi and bassist Yusuke Takeda. Radwimps immediately began recording new songs, and by July had released a second single, "Kiseki", and performed a three-month Japan-wide tour. Right after the end of the tour, the band started work on their second album, Radwimps 2: Hatten Tojō, which was finalized by the end of the year and released in March. Directly after the release, the group departed on a five-month Radwimps Haruna Tour (はるなっTOUR) and also performed at high-profile summer music festivals, such as Setstock, Rock in Japan, and Summer Sonic. During this time, the band released a third single, "Hexun / Kanashi", which was their first charting release.

In November 2005, the band made their major debut under Toshiba EMI's Virgin Records label, with the single "Nijūgoko-me no Senshokutai", followed by "EDP (Tonde Hi ni Iru Natsu no Kimi)" in January, both of which rose to the top 50. In shifting to a major label, Noda explained that the band took the same stance as they had as an independent group, and that "If we thought we were bigger on a major label, that would have been a big mistake". The band's third and first major-label album, Radwimps 3: Mujintō ni Motte Ikiwasureta Ichimai, regraded 3 in March 2006, was a landmark in establishing their popularity, debuting at number 13 on the Oricon Albums Chart. Radwimps 3 saw a change in the band's musical style, allowing them to be more experimental in their sound.

By the end of 2006, the band's popularity had increased significantly: their album Radwimps 4: Okazu no Gohan, led by the top-20 singles "Futarigoto" and "Yūshinron" and the top-5 "Setsuna Rensa", debuted at number five and had an initial shipment of more than 100,000 copies. At this time, the band's older releases, such as Radwimps, Radwimps 2, and "Kiseki", began charting for the first time, with Radwimps eventually being certified Gold by the Recording Industry Association of Japan. In the next three years, both Radwimps and Radwimps 2 charted for approximately 100 weeks, and as of early 2011, Radwimps 3 and Radwimps 4 still continued to chart.

In 2008, the band achieved their first number-one single, with "Order Made", on the Oricon charts. Their 2009 album, Altocolony no Teiri, sold around 213,000 copies in its first week, debuting at number two on the Oricon charts. The band achieved their second Oricon number-one single, "Dada", in 2011.