An American musician, best known as a founding member of the Eagles but who also played in other Southern California bluegrass and country rock groups of the 1960s including the Flying Burrito Brothers and Dillard & Clark. He is a multi-instrumentalist (guitar, banjo, mandolin, steel guitar) coming from a bluegrass background and introduced elements of this music to a mainstream audience during his time with the Eagles. He is seen as a key contributor to the development of country rock.

In the mid 1960s Leadon attended high school in Gainesville, Florida, where one of his classmates was Don Felder, who years later was his bandmate in the Eagles. Felder was a member of a band called the Continentals with Stephen Stills. Leadon ended up replacing Stills in the band, which was renamed the Maundy Quintet.

Leadon played with various Southern California bluegrass and country rock groups in the late 1960s, including the Scottsville Squirrel Barkers (with Chris Hillman), Hearts & Flowers, the Flying Burrito Brothers and Dillard & Clark, featuring his work on dobro, banjo and mandolin as well as guitar. He also developed his songwriting skills during this period, writing God's Own Singer (used as Gram Parsons' epitaph on his gravemarker) and co-writing Train Leaves Here This Morning with Gene Clark.

He backed Linda Ronstadt alongside Glenn Frey, Don Henley and Randy Meisner until the quartet tendered their resignation en masse in 1971 and formed the Eagles (the name was a nod to the Byrds). Leadon arranged the intricate harmonies on several of the early Eagles albums and wrote or co-wrote many of their songs, including Witchy Woman. He is responsible for the strong country flavour of the earlier albums, but as the band veered more and more towards harder rock his influence decreased.

Conflicts about the band's direction as well as personality clashes led to Leadon leaving the band in December 1975 after completing and touring for the Eagles' fourth studio album, One of These Nights. He had already brought in his old friend Don Felder for the On The Border album and he was replaced by rock guitarist Joe Walsh.

After the Eagles, Leadon went back to a more country sound. His first solo album was Natural Progressions (1977), but after this he largely stayed behind the scenes, contributing to other albums or taking a lower profile in other bands.

In 1998, Leadon temporarily reunited with all the members past and present of the Eagles in New York for the Rock'n'Roll Hall of Fame and they performed together on Take It Easy and Hotel California (although Leadon was not in the band when the latter was released).

Leadon released his second solo album, Mirror, in 2004, 27 years after the release of his first. He continues to perform, mostly at corporate events and private shows.