Greatest Hits is the first compilation album by American pop group The 5th Dimension, released in 1970 by Soul City. It includes all but two of their charting singles to date: "Go Where You Wanna Go", their first Top 20 record in the USA, would appear on the follow-up compilation, The July 5th Album, released later that year, while "Another Day, Another Heartache" was not included in either compilation. Greatest Hits and The July 5th Album were the final 2 album releases for Soul City Records' distribution deal with Liberty Records. The 5th Dimension subsequently signed with Bell Records.
Greatest Hits remained in print until replaced by Bell Records' 1972 compilation album, Greatest Hits on Earth which confirmed The 5th Dimension's enduring popularity by charting at #14 in the year of its release. Greatest Hits on Earth remained in print for decades.
The version of Aquarius/Let the Sunshine In included here is a shortened version of the 4:49 single release, which was the #1 hit of 1969. It omits the reprise of the first verse. No mention of this being a shortened version of the hit is made on the album cover.
The Worst That Could Happen was not a hit for The 5th Dimension, as it was not released as a single. Johnny Maestro & The Brooklyn Bridge had a hit with the song in early 1969. However, The 5th Dimension's version came first, released on their album entitled The Magic Garden.
The Girls' Song is the 5th Dimension's final single release on Soul City, and was issued specifically to coincide with this album. Originally appearing on The Magic Garden, the single was the band's least successful in three years, due in part to competing with Bell Records' release of new material.