"All You Need Is Love" is a song written by John Lennon and credited to Lennon/McCartney. It was first performed by The Beatles on Our World, the first live global television link. Watched by 400 million in 26 countries, the programme was broadcast via satellite on 25 June 1967. The BBC had commissioned the Beatles to write a song for the UK's contribution. Rolling Stonemagazine ranked it at #362 in their 500 greatest songs of all time.

The Beatles were asked to come up with a song containing a simple message to be understood by all nationalities. "It was an inspired song and they really wanted to give the world a message," said Brian Epstein. "The nice thing about it is that it cannot be misinterpreted. It is a clear message saying that love is everything." According to journalist Jade Wright, "Lennon was fascinated by the power of slogans to unite people and never afraid to create art out of propaganda. When asked in 1971 whether songs like Give Peace a Chance and Power to the People were propaganda songs, he answered: 'Sure. So was All You Need Is Love. I'm a revolutionary artist. My art is dedicated to change.'"

The day before the Our Worldbroadcast, the Beatles decided that the song should be their next single. Released in the UK on 7 July, it went straight to number one and remained there for three weeks. It was similarly successful in the US after its release on 17 July, reaching number one for a week. It was also included on the American LP version of Magical Mystery Tourin November).

The interviews on The Beatles Anthologydocumentary series reveal that Paul McCartney and George Harrison were unsure whether the song was written for Our World. However, George Martin and Ringo Starr assert it was. When asked, McCartney replied:

"I don't think it was written specially for it. But it was one of the songs we had. [...] It was certainly tailored to it once we had it. But I've got a feeling it was just one of John's songs that was coming there. We went down to Olympic Studios in Barnes and recorded it and then it became the song they said, 'Ah. This is the one we should use.' I don't actually think it was written for it."

For the broadcast, the Beatles were (except for Starr) seated on stools, accompanied by a small studio orchestra. They were surrounded by friends and acquaintances seated on the floor, who sang with the refrain during the fade-out, including Mick Jagger, Marianne Faithfull, Keith Richards, Keith Moon, Eric Clapton, Pattie Harrison, Jane Asher, Mike McCartney, Graham Nash, Gary Leeds and Hunter Davies.

The performance was not completely live: The Beatles, the orchestra, and guests were overdubbing onto a pre-recorded rhythm track mainly consisting of piano, harpsichord, drums, and backing vocals. The full Our Worldsegment opens with the band and company listening to the raw backing track, as commentator Steve Race explained the process in voiceover. The live overdubs seem to include not only lead vocals, orchestra, and the improvised call-and-response, but also bass guitar, Harrison's guitar solo, and a second drum track — which seems to go out of time with the original track during the first few bars. At the beginning of the song, under "La Marseillaise," a tambourine is shaken, but this was mixed out and replaced with a drum roll before the single was released.

Lennon, affecting indifference, was said to be nervous about the broadcast, given the potential size of the international TV audience. Dissatisfied with his singing, he re-recorded the solo verses for use on the single. Starr also overdubbed drums before the single was released, fixing the aforementioned timing problems and adding the drum roll.

The programme was broadcast in ‘black-and-white’ (colour television had yet to commence broadcasting in Britain and most of the world). The Beatles' footage was colourised, based on photographs of the event, for The Beatles Anthologydocumentary.

Because of the worldwide broadcast, the song was given an international feel, opening with the French National anthem "La Marseillaise" omitting the first note, and including excerpts of other pieces during the long fade-out, including "two-part Invention #8 in F" by Johann Sebastian Bach (transposed to G and played on 2 piccolo trumpets), "Greensleeves" (played by the strings), Glenn Miller's "In the Mood" (played on a saxophone), one of the Beatles' seminal hits (particularly in Great Britain and the United States), "She Loves You" (ad libbed by Lennon and McCartney), and Jeremiah Clarke's "Prince of Denmark's March" lilting off at the end. Many sources, including Beatles' producer George Martin, have misremembered or misidentified the Bach quote as being from the "Brandenburg Concerto No. 2". Lennon can also be heard scatting what sounds like the title of "Yesterday", though others maintain he is saying "Yes, you can." (Interestingly, the vocal chart for this song on The Beatles: Rock Band lists the lyric as "yesterday")

The structure of the song is complex. The main body (the verse) is in a 7/4 time signature with two measures of 7/4, one of 8/4, then back to 7/4 with the intro background vocals repeatedly singing "Love, love, love", over the top of which enter Lennon's lyrics:

By contrast, the chorus is simple: "All you need is love", in 4/4 time repeated against the horn response but, each chorus has only seven measures as opposed to the usual eight, and the seventh is 6/4, then back to the verse in 7/4.

"All You Need Is Love" remains one of only two songs (along with Pink Floyd's "Money" from 1973) written in 7/4 time to reach the top 20 in the United States.

In the film Yellow Submarine(1968), the second verse as well as the instrumental are deleted. Also, the last choruses are switched, the "all together now", and "everybody" coming first before the last group of choruses.