Smiley Smile is the twelfth studio album by the American rock band the Beach Boys, released on September 18, 1967. Conceived as a simpler and more relaxed version of their unfinished Smile album, Smiley Smile is distinguished for its homespun arrangements, "stoned" aesthetic, and lo-fi production. Critics and fans generally received the album and its lead single, "Heroes and Villains", with confusion and disappointment. The album reached number 9 on UK record charts, but sold poorly in the U.S., peaking at number 41—the band's lowest chart placement to that point.

Following principal songwriter Brian Wilson's declaration that most of the original Smile tapes would be abandoned, the majority of the recording sessions lasted for six weeks at his makeshift home studio using radio broadcasting equipment, a detuned piano, electronic bass, melodica, found objects for percussion, and a Baldwin theater organ. The unconventional recording process juxtaposed an experimental party-like atmosphere with short pieces of music edited together in a disjointed manner, combining the engineering methods of "Good Vibrations" (1966) with the loose feeling of Beach Boys' Party! (1965). Despite leading these sessions, Wilson deliberately credited the album's production to the group collectively for the first time.

From late 1966 to mid-1967, Smile had been repeatedly delayed while the Beach Boys were subject to a considerable level of media hype proclaiming Wilson to be a "genius". After settling payment disputes with Capitol Records, Smiley Smile was distributed in collaboration with Brother Records, the band's new self-owned record company. A second single, "Gettin' Hungry", was credited to Wilson and Mike Love and failed to chart. Smile was left incomplete as the band immediately moved onto the recording of Lei'd in Hawaii, an unfinished live album featuring performances in the style of Smiley Smile, and Wild Honey, released in December 1967.

Smiley Smile has since become a critical and cult favorite, influencing the development of the lo-fi, ambient, and bedroom pop genres. It is often regarded as one of the finest chill-out albums for having positive effects on listeners experiencing an LSD comedown, a usage adopted by at least one drug clinic. In 1974, it was ranked number 64 in NME's list of the greatest albums of all time. Outtakes and session highlights from the album were included on the compilations The Smile Sessions (2011) and 1967 – Sunshine Tomorrow (2017).

The Beach Boys' album Pet Sounds, issued on May 16, 1966, was massively influential upon its release, containing lush and sophisticated orchestral arrangements that raised the band's prestige to the top level of rock innovators. Early reviews for the album in the US ranged from negative to tentatively positive, but the reception from music journalists in the UK was very favorable. The group had recently employed the Beatles' former press officer Derek Taylor as their publicist. Bothered by the Beach Boys' popular association with surf culture, leader and songwriter Brian Wilson requested that Taylor rebrand the group, resulting in Taylor spearheading a media campaign that proclaimed Wilson to be a musical genius.

In October 1966, the group followed up Pet Sounds with "Good Vibrations", a laboriously produced single that achieved major international success. By then, an album titled Smile had been conceived as an extension of that song's recording approach, with Wilson composing music in collaboration with lyricist Van Dyke Parks. Wilson envisioned Smile as an outlet for all of his intellectual occupations, such as his fascination with spirituality and its relationship to humor and laughter. He told Melody Maker: "Our new album will be better than Pet Sounds. It will be as much an improvement over Sounds as that was over [our 1965 album] Summer Days." By the end of the year, NME conducted an annual reader's poll that placed the Beach Boys as the world's top vocal group, ahead of the Beatles and the Rolling Stones.

Wilson enlisted talent manager David Anderle in the formation of Brother Records, an independent label, with the intention of giving "entirely new concepts to the recording industry, and to give the Beach Boys total creative and promotional control over their product", according to Anderle. A February 1967 lawsuit seeking $255,000 (equivalent to $2.46 million in 2025) was launched against Capitol Records over neglected royalty payments. Within the lawsuit, there was also an attempt to terminate the band's contract with Capitol before its November 1969 expiration. In April 1967, Wilson and his wife put their Beverly Hills home up for sale and took residence at a newly purchased mansion in Bel Air. Wilson also set to work on constructing a personal home studio.

Parks permanently withdrew from the project in April, with Anderle following suit weeks later. Between mid-April and early May, Wilson took a four-week break from studio recording. On April 26, Carl Wilson was arrested for refusing his draft into the US Army and later released on bail. On April 28, in an effort to promote the group's upcoming UK tour, EMI issued the single "Then I Kissed Her" to the chagrin of the band, who did not approve the release. On May 6, a week after stating that Smile was to be released "any moment", Taylor announced in Disc & Music Echo that the album had been "scrapped" by Wilson. However, Taylor's assertion of the album's cancellation at that point was likely to be spurious. The Beach Boys were still under pressure and a contractual obligation to deliver an album to Capitol. For most of May, the touring group embarked on a run of shows in Europe while Brian resumed scheduling recording sessions at professional studios, some of which were cancelled on short notice.