The album was originally released by Asylum in the LP format in September 1977. Later, in 1986, Asylum released the album in the Cassette format and in the CD format. The album has never been out of print. One of the most successful albums of Ronstadt's career, Simple Dreams spent five successive weeks at number 1 on the Billboard album chart in late 1977, displacing Fleetwood Mac's Rumours after it had held that position for a record-breaking 29 weeks. It also knocked Elvis Presley out of the number 1 position on the Billboard Country Albums chart after "The King" had held it for fifteen consecutive weeks following his death in August. Simple Dreams was Ronstadt's fifth consecutive million-selling platinum album and sold over 3½ million copies in less than a year in the United States alone—a record for a female artist. Among female recording artists at that time, only Carole King, with her album Tapestry, had sold more copies of one album. The album was such a success that Ronstadt became the first female artist—and the first act overall since The Beatles—to have two singles in the top five at the same time: the Platinum-certified "Blue Bayou" and "It's So Easy". "It's So Easy" was originally recorded by Buddy Holly and The Crickets in 1958 but had failed to chart in its original version. It was Ronstadt's second cover of a Holly song to become a hit in as many years; she had taken a rousing cover of "That'll Be the Day" to #11 Pop in 1976, using a similar arrangement. The album includes songs by Warren Zevon, Eric Kaz, and J.D. Souther, as well as The Rolling Stones' "Tumbling Dice". Ronstadt was joined by Parton on the traditional ballad "I Never Will Marry", which became a Top 10 Country hit during the summer of 1978. Ronstadt also recorded a Spanish-language version of "Blue Bayou" entitled "Lago Azul" only released as a single in 1978. The album's 40th anniversary reissue in 2017, augmented by the addition of four live tracks, likewise omits this recording. Originally, the cover photograph was to show Ronstadt dressed in a mini-slip and seated in front of multiple mirrors. Uncomfortable with the physical exposure, she changed into a robe, and the picture was made artificially grainy. A retouched photo from the original photo sessions was included on the inner sleeve of her platinum-plus album Greatest Hits, Volume 2, released in 1980. At the 20th Grammy Awards, John Kosh won the Grammy Award for Best Recording Package for Simple Dreams.
"Blue Bayou" was nominated for the Record of the Year Grammy award in early 1978. It also earned Ronstadt a Grammy nomination for Best Pop Vocal Performance Female, alongside Barbra Streisand, Dolly Parton, Carly Simon, and Debby Boone.