The original single was credited to Inez Foxx with vocal accompaniment by her brother Charlie, as they alternated the lyric on a syllabic basis. Considered something of a novelty song, it was a great success for them upon its release by Sue Records (Symbol Records), reaching number 2 on the U.S. Top Black Singles / Rhythm & Blues chart and number 7 on the U.S. popular music singles chart in late 1963.Chris Blackwell of Island Records company heard "Mockingbird" playing in a record store in Kingston, Jamaica and flew to New York City to negotiate the track's UK release; resultantly Island Records leased the Sue brand for UK distribution in order to vend the American company's output in the UK, beginning with "Mockingbird" in December 1963. However "Mockingbird" would not become a UK success until its 1969 re-issue when it scored #33.
The song was covered by Dusty Springfield for her 1964 album A Girl Called Dusty; Springfield sang both parts of the track. "Mockingbird" was also recorded by Aretha Franklin for her 1965 album Runnin' Out of Fools; Franklin performed "Mockingbird"—with Ray Johnson providing the counter-vocal—on the 10 March 1965 episode of the program Shindig. Franklin's version of "Mockingbird" was one of several tracks to which Columbia Records company gave a single release after the singer's commercial success with Atlantic Records in 1967; released at the same time as Franklin's Atlantic single album "Chain of Fools"—which would reach #2—Franklin's version of "Mockingbird" scored two weeks at #94 on the Billboard Hot 100 in December 1967.
Carly Simon and James Taylor recorded a remake of "Mockingbird" in the autumn of 1973, and the track was released as the lead single from Simon's album Hotcakes. It was Taylor's idea to remake "Mockingbird", which he knew from a live performance by Inez and Charlie Foxx at the Apollo Theater in 1965, and which song Taylor and his sister Kate Taylor had often sung for fun as teenagers. Featuring a considerable lyrical adjustment by Taylor and keyboard work from Dr. John, Robbie Robertson's rhythm guitar and a tenor saxophone solo by Michael Brecker, "Mockingbird" rose to #5 in March 1974. The Simon/Taylor version of "Mockingbird" also charted in Canada (#3), New Zealand (#6), South Africa (#13),  the UK (#34) and Australia (see subsection below).
Carly Simon overcame her fear of live performing to come onstage to sing "Mockingbird" with Taylor during his 1975 tour; the duo also performed "Mockingbird" live at the No Nukes Concert at Madison Square Gardens in September 1979, the performance being recorded for the No Nukes: The Muse Concerts for a Non-Nuclear Future album and also the movie No Nukes. In recent years Taylor has performed "Mockingbird" live with his daughter (by Simon) Sally Taylor and Simon has performed the song live with her and Taylor's son Ben Taylor.
The 1999 Jim Brickman album Visions of Love features Carly Simon singing "Hush Little Baby"—as "Hush Li'l Baby"—which Brickman chose for Simon because "I thought it would be cool if she was singing about the mockingbird since she had a Top 5 [success with "Mockingbird"] in 1974".
In Australia, the Simon/Taylor version of "Mockingbird" charted simultaneously with another version - this one featuring the original lyrics - by Johnny O'Keefe sung with his resident background vocalist Margaret McLaren; the two versions were ranked in tandem on the charts, peaking at #8 for four weeks beginning in May 1974. O'Keefe, who had performed "Mockingbird" in 1964 as compere of the Sing Sing Sing musical show, had recorded the track with McLaren in October 1972, the track having a single release in 1973 and appearing on the local "hit parade" in Adelaide that November around the time the Simon/Taylor version was recorded; O'Keefe, who believed that the Simon/Taylor version was effectively a cover version resulting from Festival Records company selling the O'Keefe version to American record companies, lobbied the Minister for Media and the Broadcasting Control Board to have his version of "Mockingbird" receive at least equal broadcasting time with the Simon/Taylor version on Australian radio.
In the Australian stage musical Shout! based on Johnny O'Keefe's life, the characters of O'Keefe and of his mother Thelma perform "Mockingbird" as part of a sequence dramatizing O'Keefe's 1975 This is Your Life appearance. The musical opened 4 January 2001 with David Campbell and Trisha Noble as respectively Johnny and Thelma; Campbell and Noble recorded their version of "Mockingbird" for the Shout! soundtrack album released that March.
The Belle Stars did a cover version of the song Mockingbird in 1982. It was released as their third and final cover. It peaked at #51 in the charts, although the single after it, Sign of the Times, peaked at #3. It was the third single from the band's only self-titled album.
In The Simpsons episode Three Gays of the Condo (2003), Marge and Homer sing the opening from the James Taylor/Carly Simon version of the song after Marge finds a puzzle piece that has James Taylor's face that is part of a jigsaw puzzle that the Simpsons put together.