"Why Can't We Be Friends?" is a song by the band War. The song has a simple structure, with the phrase "Why can't we be friends?" being sung four times after each two-line verse amounting to over forty times in under four minutes. The song reached #6 on the Billboard Hot 100 in the summer of 1975. It was played in outer space when NASA beamed it to the linking of Soviet cosmonauts and U.S. astronauts for the Apollo–Soyuz Test Project.Billboard ranked it as the No. 23 song of that year.

The song is played during the freshman hazing scene in Dazed and Confused. It also plays over the end credits in Lethal Weapon 4 during the farewell montage (which shows flashback photographs from all four of the films), was covered in BASEketball and Bridge to Terabithia, and was played in The Final Destination. A clip of the song is played as Homer Simpson's entrance music in Season 8 Episode 3 of The Simpsons, "The Homer They Fall". The Smash Mouth version was used for commercials and TV spots for the film Ice Age. The song was also used in the intro video of the video game Operation Flashpoint: Red River. The opening of the song was used in a trailer for W. Kamau Bell's United Shades of America show on CNN.

American pop rock band Smash Mouth covered the song on their debut album Fush Yu Mang on April 7, 1998, releasing it as their second single.

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