"The Best Things in Life Are Free" is a duet between American singers Luther Vandross and Janet Jackson, recorded for the Jimmy Jam and Terry Lewis produced soundtrack to the 1992 American film Mo' Money, starring Damon Wayans. The song was composed by Jam, Lewis, Michael Bivins, Ronnie DeVoe, Harry Wayne Casey and Richard Finch. The song was released as the soundtrack's lead single on May 12, 1992, by Perspective Records and A&M Records. Additionally, the song was remixed by David Morales, Frankie Knuckles, and CJ Mackintosh. The duet became a major hit in several countries, peaking at number two in Australia and the United Kingdom, number six in Ireland and New Zealand, number eight in Canada and Germany, and number 10 in the United States. The song was nominated for the Grammy Award for Best R&B Performance by a Duo or Group with Vocals.

The song was later included on Vandross' compilations One Night with You: The Best of Love, Volume 2 and Lovesongs, as well as Jackson's own compilations Design of a Decade: 1986–1996 and Number Ones respectively. In 1995, the song was re-released as the second single from Jackson's aforementioned Design of a Decade 1986–1996 compilation album, included new remixes by Roger Sanchez, K-Klass and MK, exclusively in European countries. A further re-release followed as a limited-edition single in 1996. Jackson included the song on her 2011 tour, Number Ones, Up Close and Personal, and her 2015–2016 Unbreakable World Tour. It is also included in her 2019 Las Vegas Residency Janet Jackson: Metamorphosis.