Led Zeppelin III is the third album by the English rock band Led Zeppelin, released on 5 October 1970. It was recorded in three locations. Much of the work was done at Headley Grange, a country house, using the Rolling Stones Mobile Studio. Additional sessions were held at Island Studios and Olympic Studios in London. As with the prior album, the band eschewed the use of guest musicians, with all music performed by band members Robert Plant (vocals), Jimmy Page (guitars), John Paul Jones (bass, keyboards), and John Bonham (drums). The range of instruments played by the band was greatly enhanced on this album, with Jones especially emerging as a talented multi-instrumentalist, playing a wide range of keyboard and stringed instruments, including various synthesizers, mandolin and double bass, in addition to his usual bass guitar. As with prior albums, Page served as producer on the album, with mixing done by Andy Johns and Terry Manning.

The album showed a progression from straightforward rock towards folk and acoustic music. While hard rock influences were still present, such as on "Immigrant Song", acoustic-based songs such as "Gallows Pole" and "That's the Way" showed Led Zeppelin were capable of playing different styles successfully. The band wrote most of the material themselves, but as with prior records, included two songs that were re-interpretations of earlier works: "Gallows Pole", based on a traditional English folk song, by way of American singer Fred Gerlach; and "Hats Off to (Roy) Harper", a reworking of a blues song by Bukka White. The acoustic material developed from a songwriting session between Plant and Page at Bron-Yr-Aur cottage in Wales, which influenced the musical direction.

The album was one of the most anticipated of 1970, and its shipping date was held up by the intricate inner sleeve design based around a volvelle, with numerous images visible through holes in the outer cover. It was an immediate commercial success upon release and topped the UK and US charts. Although many critics were initially confused over the change in musical style and gave the album a mixed response, Led Zeppelin III has since been acknowledged as representing an important milestone in the band's history and a turning point in their music.