"Endless Love" is a song written by Lionel Richie and originally recorded as a duet between Richie and fellow soul singer Diana Ross. In this ballad, the singers declare their "endless love" for one another. It was covered by soul singer Luther Vandross with R&B singer Mariah Carey and also by country music singer Shania Twain. Richie's friend (and sometimes co-worker) Kenny Rogers has also recorded the song. Billboard has named the original version as the greatest song duet of all-time.

Ross and Richie recorded the song for Motown, and it was used as the theme for the Franco Zeffirelli's film adaptation of Scott Spencer's novel Endless Love. Produced by Richie and arranged by Gene Page, it was released as a single from the film's soundtrack in 1981. While the film Endless Love was a modest box-office success, the song became the second biggest-selling single of the year (first was "Bette Davis Eyes" by Kim Carnes) in the U.S. and reached number 1 on the Hot 100, where it stayed for nine weeks from August 15 to October 10, 1981. It also topped the Billboard R&B chart and the Adult Contemporary chart, and reached number 7 in the UK.

The soulful composition became the biggest-selling single of Ross' career, and her 18th and final career number-one single (including her work with The Supremes). It also was Richie's highest charting single, and the first of several hits for Richie during the 1980s. Ross recorded a solo version of the song for her first RCA Records album, Why Do Fools Fall in Love, the duet version being her last hit on Motown. The song was nominated for an Academy Award for Best Original Song for Richie, and was the second song with which Ross was involved that was nominated for an Oscar. It also won a 1982 American Music Award for Favorite Pop/Rock Single.

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