"Revolver" is a song by American singers Madonna and Lil Wayne, included on the former's third compilation album, Celebration (2009). The song was written by Madonna, Wayne, Carlos and Steven Battey, DJ Frank E, and Brandon Kitchen. Production was in charge of Madonna and Frank E. An electropop song with elements of R&B, its lyrics compare love and sex to violence and a revolver. David Guetta, Paul van Dyk, and Tracy Young created the track's official remixes. Following a leak in May 2009, the song was released as the compilation's second single on December 29.

Upon release, critics reacted ambivalently towards "Revolver". Wayne's verse was praised by some, while others deemed the track generic and underwhelming. The song's One Love Mix by David Guetta was awarded Best Remixed Recording, Non-Classical at the 53rd Annual Grammy Awards. "Revolver" had a lukewarm chart performance. It reached the fourth spot of Billboard's Hot Dance Club Songs chart, while Guetta's remix peaked within the top 30 and 20 in Belgium and Italy. Madonna sang the track on the MDNA Tour of 2012. The use of firearms in the performance caused controversy, especially after the 2012 Aurora, Colorado, shooting.

In March 2009, Liz Rosenberg, Madonna's publicist, confirmed that she would be releasing a new compilation album from the first three decades of her musical career, with a planned release date of September. Three months later, Billboard magazine reported that the compilation ―named Celebration― would feature two new songs: the title track, produced by British DJ Paul Oakenfold, and "Revolver", a collaboration with rapper Lil Wayne. The latter was included only on the album's double-disc edition. "Revolver" was written by Madonna, Lil Wayne, Carlos and Steven Battey, DJ Frank E, and Brandon Kitchen. Production was in charge of the singer Frank E. Demacio Castellon did the mixing while the Pro Tools editing was arranged by Ron Taylor from Warner Bros. Records. During an interview, Frank E revealed that he'd gone to the studio two hours before his scheduled meeting with Madonna to set up and give the audio files to the recording engineer, and that the subsequent wait was incredibly nerve-wrecking for him. After the singer arrived, they recorded her vocals and the song was finished the next day. Official remixes were created by David Guetta, Paul van Dyk, and Tracy Young. While recalling his involvement with the song, Frank E expressed his gratitude at having had the opportunity to work with Madonna, but wasn't pleased with the final result:

"I will never forget the feeling of leaving that session after vocal producing [Madonna], and thinking to myself, 'it can’t it really get any harder than this'. I've taken that mentality into every other session I've been in, and it's helped me make the session and song more of a success. Unfortunately, the mix sounded like crap and the song flopped, but hey, you win some and you lose some".

Musically, "Revolver" has been noted as recalling the "electro R&B" from Madonna's eleventh studio album, Hard Candy (2008). It presents "sirenesque" synths, and shares its title with a Lil Wayne song, and a movie directed by Guy Ritchie, Madonna's former husband. According to the sheet music published by Alfred Publishing Inc., "Revolver" is set in the common time with a moderate tempo of 120 beats per minute. It follows in the basic sequence of B♭m–D♭–A♭–B♭m–D♭–A♭ as its chord progression, while Madonna's voice spans from the tonal nodes of A♭₃ to E♭₅.

The lyrics equate love and sex to violence and a revolver; My love's a revolver/My sex is a killer/Do you wanna die happy?, she sings in the refrain. The bridge has Wayne, "[giving] himself loads of big-ups when it comes to the women": The victim didn't complain, she just screamed, 'Shoot again'/I gave her extra rounds/My barrel twist around/I am Mr. Shoot 'Em Down/I leave hearts on the ground. An early demo of "Revolver" leaked on May 11, 2009, while the final version debuted online three months later, on September 17. Remixes and physical releases were issued from December 29 to February 10, 2010.

Critical feedback towards "Revolver" was mixed. Rolling Stone's Daniel Krepps felt the final version was more befitting to Madonna than the leaked demo, and compared it to "Radar" (2009) by Britney Spears. He concluded by referring to the track as, "probably the most violent love song ever". Also from Rolling Stone, Rob Sheffield wrote: "[Madonna's] hitmaking genius is unmatched and —with the new Eurocheeseblast 'Celebration' and the Lil Wayne duet 'Revolver'— undiminished". From Entertainment Weekly, Leah Greenblatt considered the track a "glitched-out dance-floor stomper". Writing for MTV, Shaheem Reid said "Revolver" was a "sugary ditty", and singled out Lil Wayne's verse. On this vein, The Daily Telegraph's Sarah Crompton said "Revolver" shows off Lil Wayne's skills as a singer better than Madonna's. By contrast, Slant Magazine's Eric Henderson deemed it a "clumsy" collaboration.

Joey Guerra from the Houston Chronicle said it was a generic track that was, "more filler than truly fascinating". Joseph Brannigan Lynch from Entertainment Weekly deemed it underwhelming; "[A]nyone hoping this collaboration with Wayne would mean a new direction for [Madonna] will be disappointed. 'Revolver' is [...] not bad by any stretch, but it certainly won't end up on the next greatest-hits collection she releases ten years from now". The author, nonetheless, singled out the "charmingly frivolous lyrics". The Guardian's Jude Rogers was not impressed with the track's lyrical theme: "Madonna loves metaphors [but] there have been better ideas". Paul Schrodt from Slant Magazine wrote: "Forget the uncharacteristic desperate crassness of choosing the then-hot Lil Wayne as a collaborator. Also, ignore the half-heartedness of the track’s electroclash gestures. What you have left is a sex-equals-guns metaphor that, with each passing year in America, grows more and more tone deaf".