"Blue Bayou" is a song written by Roy Orbison and Joe Melson. It was originally sung and recorded by Orbison, who had an international hit with his version in 1963. It later became Linda Ronstadt's signature song, with which she scored a Top 5 hit with her cover in 1977. Many others have since recorded the song.

Linda Ronstadt took the song to #3 on the Billboard Hot 100 in late 1977, where it held for four weeks, as well as #2 Country and #3 Easy Listening. It also reached #2, holding there for four weeks, on the Cash Box Top 100 chart.

The single was RIAA certified Gold (for sales of over 1 million US copies) in January 1978. It was the first of Ronstadt's three Gold singles. Don Henley of the Eagles sang backup on the recording. "Blue Bayou" was later certified Platinum (for over 2 million copies sold in the United States). It was a worldwide smash, charting in countries such as Australia, Canada, New Zealand, the United Kingdom, and Mexico, where it topped the singles charts.

Ronstadt's version was nominated for the Grammy Award for Record of the Year and for Best Female Pop Vocal Performance.

Ronstadt also recorded a Spanish-language version of the song, titled "Lago Azul (Blue Bayou)", which was released in 1978 on the single Asylum E-45464, backed by "Lo Siento Mi Vida", a previously released Spanish song that Ronstadt herself co-wrote. This version has never been included on any reissues of Simple Dreams.

Ronstadt later performed the song on episode 523 of The Muppet Show, first aired on October 26, 1980, in the UK, and May 16, 1981, in the United States.