"The Long and Winding Road" is a ballad written by Paul McCartney (credited to Lennon/McCartney) that originally appeared on The Beatles' album Let It Be. It became The Beatles' last number-one song in the United States on 23 May 1970, and was the last single released by the quartet. "The Long and Winding Road" was listed with "For You Blue" as a double-sided hit when the single hit number one on the U.S. Hot 100 in 1970.

While the released version of the song was very successful, the post-production modifications to the song by producer Phil Spector angered McCartney to the point that when he made his case in court for breaking up The Beatles as a legal entity, McCartney cited the treatment of "The Long and Winding Road" as one of six reasons for doing so.

McCartney originally wrote the song at his farm in Scotland, and was inspired by the growing tension among The Beatles. McCartney said later:

McCartney recorded a demo version of the song, with Beatles' engineer Alan Brown assisting, in September 1968, during the recording sessions for The Beatles.

The song takes the form of a piano-based ballad, with conventional chord changes. The song's home key is in E-flat major but also uses relative minor; the key of C minor. Lyrically, it is a sad and melancholic song, with an evocation of an as-yet unrequited, though apparently inevitable, love.

The "long and winding road" of the song was claimed to have been inspired by the B842, a thirty-one mile (50 km) winding road in Scotland, running along the east coast of Kintyre into Campbeltown, and part of the eighty-two mile (133 km) drive from Lochgilphead. In an interview in 1994, McCartney described the lyric more obliquely:

The opening theme is repeated throughout, the song lacks a traditional chorus, and the melody and lyrics are ambiguous about the opening stanza's position in the song; it is unclear whether the song has just begun, is in the verse, or is in the bridge.

The Beatles recorded "The Long and Winding Road" on 26 and 31 January 1969, the day after the group's legendary final performance on the roof of their Apple headquarters, with McCartney on piano, John Lennon on bass guitar, George Harrison on guitar, Ringo Starr on drums, and Billy Preston on Hammond organ. This was during a series of sessions for an album project then known as Get Back. Lennon, who played bass only occasionally, made several mistakes on the recording. Some writers, such as Ian MacDonald, have postulated that the disenchanted Lennon's ragged bass playing was purposeful.

In May 1969, Glyn Johns, who had been asked to mix the Get Backalbum by The Beatles, selected the 26 January recording as the best version of the song. The Beatles had recorded a master version as part of the 'Apple studio performance' on 31 January, which had different lyrics and structure, but was not released. Bootlegs of the recording sessions of that day, and the film, show the band recording numerous takes of the song in a concerted effort to create a master. For both the 1969 and 1970 versions of the Get Backalbum, Glyn Johns used the 26 January mix as released on the Anthology 3album in 1996. When the project was handed over to Phil Spector he also chose the 26 January recording. In the spring of 1970, Lennon and The Beatles' manager, Allen Klein, turned over the recordings to Phil Spector with the hope of salvaging an album, which was then titled, Let It Be.

Spector made various changes to the songs, but his most dramatic embellishments would occur on 1 April 1970, when he turned his attention to "The Long and Winding Road". At Abbey Road Studios, he recorded the orchestral and choir accompaniment for the song. The only member of The Beatles present was Starr. Already known for his eccentric behaviour in the studio, Spector was in a peculiar mood that day, as balance engineer Pete Bown recalled: "He wanted tape echo on everything, he had to take a different pill every half hour and had his bodyguard with him constantly. He was on the point of throwing a wobbly, saying 'I want to hear this, I want to hear that. I must have this, I must have that.'" Bown and the orchestra eventually became so annoyed by Spector's behaviour that the orchestra refused to play any further, and at one point, Bown left for home, forcing Spector to telephone him and persuade him into coming back after Starr had told Spector to calm down.

Finally, Spector succeeded in remixing "The Long and Winding Road", using 18 violins, four violas, four cellos, three trumpets, three trombones, two guitars, and a choir of 14 women. The orchestra was scored and conducted by Richard Hewson, who would later work with McCartney on his album, Thrillington. This lush orchestral treatment was in direct contrast to The Beatles' stated intentions for a "real" recording when they began work on Get Back.

When McCartney first heard the Spector version of the song, he was outraged. Nine days after Spector overdubbed "The Long and Winding Road", McCartney announced The Beatles' breakup. On 14 April, he sent a sharply worded letter to Apple Records business manager Allen Klein, demanding that the added instrumentation be reduced, the harp part eliminated, and "Don't ever do it again." These requests went unheeded, and the Spector version was included on the album.

In an interview published by the Evening Standardin two parts on 22 April and 23 April 1970, McCartney said: "The album was finished a year ago, but a few months ago American record producer Phil Spector was called in by Lennon to tidy up some of the tracks. But a few weeks ago, I was sent a re-mixed version of my song 'The Long and Winding Road' with harps, horns, an orchestra, and a women's choir added. No one had asked me what I thought. I couldn't believe it." The Beatles' usual producer, George Martin, agreed, calling the remixes "so uncharacteristic" of The Beatles. McCartney asked Klein to dissolve The Beatles partnership, but was refused. Exasperated, he took the case to court, naming Klein and the other Beatles as defendants. Among the six reasons McCartney gave for dissolving The Beatles was that Klein's company, ABKCO, had caused "intolerable interference" by overdubbing "The Long and Winding Road" without consulting McCartney.

Spector claimed that he was forced into remixing "The Long and Winding Road", because of the poor quality of Lennon's bass playing. While the poor quality of the bass playing has been noted by other sources (in his book Revolution in the Head, a track-by-track analysis of the Beatles' records, Ian MacDonald described it as "atrocious" to the point of sabotage), its basis as the full-scale re-working of the track by Spector has been questioned. McCartney has argued that Spector could have merely edited out the relevant mistakes and rerecorded them, a technique Spector used elsewhere on the album. Specifically, it would have been a simple matter of having McCartney overdub a more appropriate bass part to replace the Lennon bass line that was judged to be inadequate.

The controversy surrounding the song did not prevent a chart-topping single from being released in the United States on 11 May 1970, joined by "For You Blue" on the B-side. 1.2 million copies were sold in the first two days, and the song began its ten-week long chart run on 23 May. On 13 June, it became The Beatles' twentieth and final number one single in America, according to Billboardmagazine. "The Long and Winding Road" brought the curtain down on The Beatles' six years of domination in America that began with "I Want to Hold Your Hand" in 1964. The Beatles achieved twenty number one singles in a mere space of 74 months, achieving an average of one number one single per 3.7 months.

The original Glyn Johns mix of the 26 January take without the orchestration and Spector overdubs was included on Anthology 3released in 1996. This version included a bridge section spoken, rather than sung, by McCartney.

In 2003, the remaining Beatles and Yoko Ono released Let It Be... Naked,touted as the band's version of Let It Beremixed by independent producers. McCartney claimed that his long-standing dissatisfaction with the released version of "The Long and Winding Road" (and the entire Let It Bealbum) was in part the impetus for the new version. The album included a different take, Take 19, of "The Long and Winding Road" recorded on 31 January. Although a different take, this version is nonetheless closer to McCartney's original intention than the original Let it Beversion, with no strings or other added instrumentation beyond that which was played in the studio at the time. This take is the one seen in the film Let It Be.

Ringo Starr was impressed with the Nakedversion of the song: "There's nothing wrong with Phil's strings, this is just a different attitude to listening. But it's been 30-odd years since I've heard it without all that and it just blew me away." Spector himself argued that McCartney was being hypocritical in his criticism: "Paul had no problem picking up the Academy Award for the Let It Bemovie soundtrack, nor did he have any problem in using my arrangement of the string and horn and choir parts when he performed it during 25 years of touring on his own. If Paul wants to get into a pissing contest about it, he's got me mixed up with someone who gives a shit."

After its original release, "The Long and Winding Road" became a staple of McCartney's post-Beatles concert repertoire. On the 1976 Wings Over the World Tour, where it was one of the few Beatles songs played, it was performed on piano in a sparse and effective arrangement using a horn section.

On McCartney's 1989 solo tour and since, it has generally been performed on piano with an arrangement using a synthesiser mimicking strings, but this string sound has been much more restrained than on the Spector recorded version. McCartney also played the song to close the Live 8 concert in London.

In 1990, McCartney released a live version as a 12" single with other live tracks from his repertoire.

McCartney re-recorded "The Long and Winding Road" for the soundtrack to his 1984 film, Give My Regards to Broad Street. Some of the elements of the 1970 Spector remix that McCartney had disliked—a choir and a lush string arrangement—were repeated by McCartney and producer George Martin for the soundtrack re-recording.

McCartney made another studio recording of the song during the 1989 Flowers in the Dirtsessions; it was released that year as a B-side to the single "This One".