Sharon Myers adopted the name Jackie DeShannon, believed to be an Irish ancestor. Record company executives at Liberty Records thought the name Sharon Myers wouldn't sell records.

Jackie DeShannon was born in Hazel, Kentucky. The daughter of showbusiness parents, Sandra Jean and James Erwin Myers, DeShannon was introduced to singing country tunes on a local radio show at the age of six. By the age of eleven, DeShannon was already hosting her own radio program. Recording under various names such as Sherry Lee, Jackie Dee, and Jackie Shannon, she had little success however her interpretations of country songs, "Buddy" and "Trouble", gained the attention of Eddie Cochran who arranged for her to travel to California and meet singer songwriter Sharon Sheeley, who formed a writing partnership with DeShannon in 1960. The partnership produced hits such as "Dum Dum" and "He's the Great Imposter" for Brenda Lee and The Fleetwoods respectively. DeShannon was then commissioned to write the soundtrack for the 1961 film Splendor in the Grass.

In 1962, DeShannon signed with Liberty Records and recorded "Needles and Pins" and "When You Walk in the Room", with both resulting in major American hits. English group The Searchers later covered both songs in 1963 for success on the UK charts. She recorded many other singles that encompassed teen pop, country ballads, rockabilly, gospel and Ray Charles style soul that didn't fare as well on the charts. During these years it was her songwriting and public profile, rather than her singing, which kept her contracted to Liberty Records. DeShannon dated Elvis Presley and formed friendships with The Everly Brothers and Ricky Nelson. She also co-starred and sang with Bobby Vinton in the teen surf movie Surf Party.

DeShannon's biggest break came in February, 1964 when she supported The Beatles on their first US tour, and formed a touring band with guitarist Ry Cooder. DeShannon also wrote "Don' Doubt Yourself Babe" for The Byrds debut album. Her music at this stage was heavily influenced by the American West Coast sounds and folk music. Staying briefly in England in 1965, DeShannon formed a songwriting partnership with Jimmy Page, which resulted in hit singles "Dream Boy" and "Don't Turn Your Back on Me". Both Page and DeShannon also wrote material for singer Marianne Faithfull including her Top Ten UK and US hit "Come and Stay with Me". DeShannon also appeared on the television show Ready Steady Go!.

Moving to New York, DeShannon co-wrote with Randy Newman producing such songs as "She Don't Understand Him" and "Did He Call Today Mama" as well as writing "You Have No Choice" for Delaney Bramblett. In late 1965, DeShannon recorded Bacharach and David's "What the World Needs Now Is Love" and it provided her first Number 1 hit and regular appearances on television shows and club tours. (DeShannon's recording of the song was subsequently used in the 1969 film Bob & Carol & Ted & Alice.) She appeared in the 1967 film C'mon Let's Live a Little with Bobby Vee, as a folk singer. DeShannon continued writing and recording but it wasn't until 1968 when she scored her next biggest smash single and album, both entitled Put a Little Love in Your Heart. The single "Love Will Find a Way" off the same album was also a moderate hit. Switching to Atlantic Records in 1970 and moving to Los Angeles, DeShannon recorded the critically acclaimed albums Jackie and Your Baby Is a Lady but they failed to produce the same commercial successes of previous releases. In 1973 she was invited by Van Morrison to sing on his Hard Nose the Highway album.

Put a Little Love in Your Heart was performed as the closing number at the Music for UNICEF Concert, broadcast worldwide from the United Nations General Assembly in 1979.

While DeShannon has not produced any further Top Ten singles of her own, her songs have been covered by other artists who have in turn converted them into hits. In 1975 with Donna Weiss, she composed "Queen of the Rodeo" and "Bette Davis Eyes" for her album New Arrangement. The song "Bette Davis Eyes" later became a worldwide Number 1 single for singer Kim Carnes in 1981. It earned DeShannon the 1982 Grammy Award for Song of the Year.

The songs "Breakaway" recorded by Tracey Ullman in 1983 and "Put a Little Love in Your Heart" recorded by Annie Lennox and Al Green in 1988 also became huge hits, the latter of which Dolly Parton also covered in 1993. A version of "When You Walk in the Room" by Pam Tillis in 1994 topped the country charts. Another recent cover of "When you Walk in the Room" was by ex ABBA vocalist Agnetha Fältskog both within her comeback album "My Colouring Book" and as a UK and European hit single.