The 5th Dimension is an American vocal group. Their music encompasses sunshine pop, pop soul, and psychedelic soul.

Formed as the Versatiles in late 1965, the group changed its name to "the 5th Dimension" by 1966. Between 1967 and 1973 they charted with 20 top 40 hits on the Billboard Hot 100, two of which – "Up, Up and Away" (no. 7, 1967) and the 1969 number one "Medley: Aquarius/Let the Sunshine In (The Flesh Failures)" — won the Grammy Award for Record of the Year. Other big hits include "Stoned Soul Picnic" (no. 3), "Wedding Bell Blues" (no. 1), "One Less Bell to Answer" (no. 2), a cover of "Never My Love" (pop no. 12/Easy Listening no. 1), "(Last Night) I Didn't Get to Sleep at All" (no. 8), and "If I Could Reach You" (pop no. 10/Easy Listening no. 1). Three of their records reached the top ten of Billboard's Rhythm & Blues/Soul chart. Five of their 19 top 20 hits on the Easy Listening chart reached number one.

The five original members were Lamonte McLemore, Marilyn McCoo, Florence LaRue, Ronald Townson, and Billy Davis Jr. Their earliest recordings were on the Soul City record label, which was started by recording artist Johnny Rivers. The group later recorded for Bell/Arista Records, ABC Records, and Motown Records.

Some of the songwriters who worked with the 5th Dimension went on to careers of their own, especially Ashford & Simpson, who wrote the song "California Soul". The group is also notable for having more success with the songs of Laura Nyro than Nyro did herself, particularly with "Stoned Soul Picnic", "Sweet Blindness", "Wedding Bell Blues", "Blowin' Away" and "Save the Country". The group also recorded songs by well-known songwriters including Burt Bacharach and Hal David ("One Less Bell to Answer") and Jimmy Webb, who wrote "Up, Up and Away". The group's 1967 LP The Magic Garden features all but one song composed by Webb.

The 5th Dimension's producer Bones Howe used Bob Alcivar as the singers' vocal arranger as well as instrumental backing by the Wrecking Crew for their recording sessions.