This was written by the Motown husband and wife songwriting duo Ashford & Simpson. Nick Ashford was inspired by an experience when he first moved to New York. He was walking down a Manhattan thoroughfare, determined that New York City would not get the best of him; the words "Ain't no mountain high enough" popped into his head.

She had many hits with The Supremes, but this was Diana Ross' first US #1 solo hit.

Marvin Gaye and Tammi Terrell recorded the original hit version peaking at #19 in the US in 1967. Uriel Jones of The Funk Brothers, who played the drums on Gaye and Terrell's original version, recalled in Mojo magazine February 2009: "Ashford and Simpson had written the song and they always came to the studio with charts. This time was no exception; they came with the song fully written out. The lyrics were written out too. They were one of the few producers and writers who had full charts and made us work from them. They knew 95 per cent what they wanted to hear. Johnny Bristol and Harvey Faqua were the actual producers in charge of the recording. We did the rhythm track first, then they put the horns on second. Then they recorded Tammi Terrell's vocal, then they did Marvin Gaye's next. Each vocal was done separately, the singer in the studio with the producer on their own, and they put it all together at the end. You know, I never heard the finished song until I switched on the radio and it was playing."

Amy Winehouse's 2007 single "Tears Dry On Their Own" is based around the backing instrumentation of this song. Ashford & Simpson were also credited on Jessica Simpson's 2006 transatlantic Top 20 single "A Public Affair," as towards the end of the song, the background vocalists can be heard singing a few lines of "aaah, aaah, aaah" in a clear duplication from "Ain't No Mountain High Enough."