"Revolution" is a song by the English rock band the Beatles, written by John Lennon and credited to the Lennon–McCartney partnership. Three versions of the song were recorded and released in 1968, all during sessions for the Beatles' self-titled double album, also known as the "White Album": a slow, bluesy arrangement ("Revolution 1") included on the album; an abstract sound collage (titled "Revolution 9") that originated as the latter part of "Revolution 1" and appears on the same album; and the faster, hard rock version similar to "Revolution 1", released as the B-side of "Hey Jude". Although the single version was issued first, it was recorded several weeks after "Revolution 1", intended for release as a single. A music video for the song was shot using the backing track from the single version, their appearances reflecting the song's atmosphere, along with live-sung lyrics that more closely resemble the album version.

Inspired by political protests in early 1968, Lennon's lyrics expressed sympathy with the need for social change but doubt in regard to the violent tactics espoused by some members of the New Left. Despite his bandmates' reservations, he persevered with the song and insisted it be included on their next single. When released in August, the song was viewed by the political left as a betrayal of their cause and a sign that the Beatles were out of step with radical elements of the counterculture. The release of "Revolution 1" in November indicated Lennon's uncertainty about destructive change, with the phrase "count me out" recorded instead as "count me out – in". Lennon was stung by the criticism he received from the New Left and subsequently espoused the need for Marxist revolution, particularly with his 1971 single "Power to the People". However, in one of the final interviews he gave before his death in 1980, he reaffirmed the pacifist sentiments expressed in "Revolution".

"Revolution" reached number 12 on the Billboard Hot 100 in the US and topped singles charts in Australia and New Zealand. "Revolution" has received praise from music critics, particularly for the intensity of the performance and the heavily distorted guitar sound. In 1987, the song became the first Beatles recording to be licensed for a television commercial, which prompted a lawsuit from the surviving members of the group. The song has been covered by numerous artists, including Thompson Twins, who performed it at Live Aid in July 1985, and Stone Temple Pilots.

In early 1968, media coverage in the aftermath of the Tet Offensive spurred increased protests in opposition to the Vietnam War, especially among university students. The protests were most prevalent in the United States, and on 17 March, 25,000 demonstrators marched to the American embassy in London's Grosvenor Square and violently clashed with police. Major protests concerning other political issues made international news, such as the March 1968 protests in Poland against their communist government, and the campus uprisings of May 1968 in France. The upheaval reflected the increased politicisation of the 1960s youth movement and the rise of New Left ideology, in a contrast with the hippie ideology behind the 1967 Summer of Love. For these students and activists, the Maoist idea of cultural revolution, purging society of its non-progressive elements, provided a model for social change.

By and large, the Beatles had avoided publicly expressing their political views in their music, with "Taxman" being their only overtly political track thus far. Viewed as leaders of the counterculture, the band – particularly John Lennon – were under pressure from Leninist, Stalinist, Trotskyist and Maoist groups to actively support the revolutionary cause. Lennon decided to write a song about the recent wave of social upheaval while the Beatles were in Rishikesh, India, studying Transcendental Meditation. He recalled, "I thought it was about time we spoke about it, the same as I thought it was about time we stopped not answering about the Vietnamese war [in 1966]. I had been thinking about it up in the hills in India." Lennon began writing the song there and completed it in England in May, inspired especially by events in France.

Despite Lennon's antiwar feelings, he had yet to become anti-establishment, and expressed in "Revolution" that he wanted "to see the plan" from those advocating toppling the system. In author Mark Hertsgaard's description, the lyrics advocate social change but emphasise that "political actions [should] be judged on moral rather than ideological grounds". The repeated phrase "it's gonna be alright" came directly from Lennon's Transcendental Meditation experiences in India, conveying the idea that God would take care of the human race no matter what happened politically. Another influence on Lennon was his burgeoning relationship with avant-garde artist Yoko Ono and her espousal of sexual politics as an alternative to Maoist ideas and other hardline philosophies adopted by the political left. Lennon credited Ono with awakening him from his passive mindset of the previous year.

Around the fourth week of May 1968, the Beatles met at Kinfauns, George Harrison's home in Esher, to demonstrate their songs to each other in preparation for recording their next studio album. A recording from that informal session released in the White Album's Super Deluxe version shows that "Revolution" had two of its three verses intact. The lines referencing Mao Zedong – "But if you go carrying pictures of Chairman Mao / You ain't gonna make it with anyone anyhow" – were added in the studio. While filming a promotional clip later that year, Lennon told director Michael Lindsay-Hogg that it was the most important lyric in the song.

The Beatles began the recording sessions for their new album on 30 May, starting with "Revolution 1" (simply titled "Revolution" for the first few sessions). At this first session, they concentrated on recording the basic rhythm track. Take 18 lasted 10:17, much longer than the earlier takes, and it was this take that was chosen for additional overdubs recorded over the next two sessions. The full take 18 was officially released in 2018, as part of the Super Deluxe Edition of The Beatles coinciding with the album's fiftieth anniversary.