"If 6 Was 9" is a song written by Jimi Hendrix and recorded by The Jimi Hendrix Experience. It appeared on the release of their 1967 album Axis: Bold as Love and on the soundtrack for the 1969 film Easy Rider.

The style of the song has been referred to as "acid-fueled blues", and the theme as an "individualist anthem". The lyrics portray the underlying conflict of the counterculture of the 1960s: the "social and cultural dichotomies" between the hippies and the "white collared conservative" business world of the establishment. Beginning with a blues riff, the lyrics accompany a "spacey" free-form jam, with Hendrix epitomizing the existentialist voice of the youth movement: "I'm the one that's got to die when it's time for me to die/so let me live my life/the way I want to."

Author Harry Shapiro believes the lyrics, "if the mountains fell into the sea" are a reference to the creation myth of the second world of Hopi mythology. Frank Waters' Book of the Hopi (1963) was known to have influenced Hendrix, and many of his songs contain mythological themes and images related to Native Americans in the United States; Hendrix himself was part Cherokee.

The guitar solo is noteworthy for making innovative use of studio technology for the time, with stereo panning from left to right and vice versa, along with other effects, such as slap echo, fuzzbox distortion, and reverb.

There is some confusion as to whether Hendrix played a flute or a soprano recorder on this track. The credits list Hendrix as playing flute, but recorder player Rodney Waterman and Joe Vanderford of Independent Weekly refer to Hendrix's instrument as a recorder. Early music enthusiast Nicholas S. Lander maintains that "the high tessitura, the typical 'breaking' between octaves, and other characteristics are more suggestive of a soprano recorder."

Various urban legends based on numerology have developed around the meaning of number 9 in the song and Hendrix's subseqent accidental death from asphyxiating on his vomit after taking a mixture of Secobarbital and alcohol in 1970.

Notable cover versions include the 1992 release by Bootsy Collins with guitarist Buckethead on Funkcrononicum. Punk-rock band Fifteen also quotes the 'White Collared Conservative Businessman' verse in their song "Brian's Song." Tori Amos covered this song on the CD Single of Cornflake Girl.