"Heart of Gold" from the 1972 album Harvestis Neil Young's only number one hit single in his long musical career. Rolling Stoneranked it #297 on their list of the 500 greatest songs of all time. It features the back-up vocals of James Taylor and Linda Ronstadt.

The song is one of a series of soft, acoustic pieces which were written partly as a result of a back injury. Unable to stand for long periods of time, he could not play his electric guitar and so returned to his acoustic guitar, which he could play sitting down.

The song was taped during the initial sessions for Harvestin early 1971 at Quadrafonic Studios in Nashville, Tennessee. Ronstadt and Taylor were in Nashville at the time for an appearance on Johnny Cash's television program, and the album's producer Elliot Mazer arranged for them to sing backup for Young in the studio.

Originally, this song was meant to segue with the song "A Man Needs a Maid", and was therefore played on piano. It was played in this manner during Young's solo shows in 1971, but he abandoned this approach midway through the tour and began to play it on guitar as it is now known. Additionally, one line that was cut when the two songs became separate entities was "Afraid/A man feels afraid" An example of the segued version appears on Young's Live at Massey Hall 1971release.

Young wrote in the liner notes of his compilation album Decade: "This song put me in the middle of the road. Traveling there soon became a bore so I headed for the ditch. A rougher ride but I saw more interesting people there." This statement was in response to the mainstream popularity that he gained as a result of "Heart of Gold"'s number-one status.

In 1985, Bob Dylan admitted that he hated this song, despite always liking Neil Young:

The only time it bothered me that someone sounded like me was when I was living in Phoenix, Arizona, in about '72 and the big song at the time was "Heart of Gold." I used to hate it when it came on the radio. I always liked Neil Young, but it bothered me every time I listened to "Heart of Gold." I think it was up at number one for a long time, and I'd say, "Shit, that's me. If it sounds like me, it should as well be me."

The song has been covered by Tanya Donelly, Matchbox Twenty, Tori Amos, Free Dominguez, Johnny Cash, Willie Nelson, Richard Lloyd, Bettye Lavette, Birds and Batteries, Zakk Wylde (with Black Label Society), Boney M, Carla Cook, Lawrence Gowan, Stereophonics, Rockapella, Roxette, Backburner, Hanah, Ossifar, the James Last Orchestra, Five for Five, Sally Dworsky, Channeling Owen, Stoney LaRue, The Bad Plus, Dave Matthews and Jimmy Buffett (with the Coral Reefer Band), and as a Karaoke backing track. It is also heard briefly in the film Iceman.

In 2005, "Heart of Gold" was named the third greatest Canadian song of all time on the CBC Radio One series 50 Tracks: The Canadian Version. It ranked behind only Barenaked Ladies' "If I Had $1000000" and Ian and Sylvia's "Four Strong Winds".