The original music score, including a title song performed by Little Richard, was by Bobby Troup, with an additional credit to Ray Anthony for the tune "Big Band Boogie". Tom Ewell had portrayed Marilyn Monroe's leading man in The Seven Year Itch the previous year.
A slot-machine mobster, Marty "Fats" Murdock (Edmond O'Brien), wants his blonde girlfriend, Jerri Jordan (Jayne Mansfield), to be a singing star, despite her seeming lack of talent. He hires alcoholic press agent Tom Miller (Tom Ewell) to promote Jordan, both because of his past success with the career of singer Julie London (a fiction of the script) and because he never makes sexual advances towards his female clients.
Miller sets to work by showing Jordan off around numerous night spots; his machinations arouse interest in Jordan and soon offers of contracts follow. However, Miller realizes that Jordan really just wants to be a homemaker and tries to persuade Murdock not to push Jordan into a show-business career. He thinks he's succeeded when he reveals to Murdock that Jordan's singing is so bad it shatters light bulbs, but Murdock suggests that Jordan would be perfect for a song he (Murdock) composed while in prison. Miller reluctantly records Jordan performing the part of a prison siren in Murdock's song and heads to Chicago to promote it to Wheeler (John Emery), a former mob rival of Murdock who now has a monopoly over the jukebox industry.
Suspicious of Miller's reluctance to promote Jordan and of the obvious attraction between Miller and Jordan, Murdock has his associate Mousie (Henry Jones) wiretap a phone call between the pair. Feeling pity for them, Mousie edits out the romantic portions of their conversations and convinces Murdock that their relationship is strictly business.
In Chicago, Wheeler is impressed by the song and Jordan's voice and offers to sign both Jordan and the song writer. However, when Miller reveals that the song writer is Murdock, Wheeler throws him out of his office and vows never to play the song. A furious Murdock bullies bar owners into buying jukeboxes from him instead and successfully promotes his and Jordan's song. To prevent Murdock from stealing his business, Wheeler arranges to have Murdock assassinated at the rock show where Jordan will be making her debut.
On his way to the show, Murdock confesses to Mousie that he doesn't want to marry Jordan. Mousie confesses that he altered the tape of Jordan and Miller's phone call and encourages Murdock to let Jordan marry Miller. Backstage at the show, Jordan confesses her love to Miller and they kiss. Jordan also admits that she is a talented singer, who lied because she did not want a show business career; she goes on stage and performs a song about her love for Miller. When Murdock arrives, Miller declares to him that he and Jordan are in love; the delighted Murdock surprises Miller by shaking his hand and offering to be the best man.
Before Miller and Murdock can tell Jordan the good news, Wheeler's assassins shoot at Murdock. Miller fights them off and shoves Murdock on stage to perform his song, reasoning that the assassins won't shoot Murdock in front of so many witnesses. Wheeler arrives and, impressed by the audience's response to Murdock, calls off the assassination and signs Murdock instead. The film ends with Miller and Jordan kissing on their honeymoon, as Murdock and Mousie perform on a TV show in the background.
The film is recognized by American Film Institute in these lists:2006: AFI's Greatest Movie Musicals – Nominated
The movie's influence on rock music is significant. The film reached Liverpool, England, in the early summer of 1957. The cameo performances of early rock 'n' roll stars such as Little Richard, Eddie Cochran, and Gene Vincent and His Bluecaps fascinated a 16-year-old John Lennon by showing him, for the first time, his "worshiped" American rock 'n' roll stars as living humans and thus further inspiring him to pursue his own rock and roll dream. On July 6, 1957, 15-year-old Paul McCartney was introduced to Lennon after the latter had performed at a village church garden party with his skiffle group The Quarrymen. McCartney demonstrated his musical prowess to Lennon by performing "Twenty Flight Rock" in a manner similar to how he had seen it played by Eddie Cochran in The Girl Can't Help It. This led to Lennon inviting McCartney to join the group. McCartney talks about the movie in the documentary series The Beatles Anthology.
On Wednesday September 18, 1968 The Beatles interrupted recording "Birthday" at Abbey Road Studios so they could go back to Paul McCartney's house to watch the British TV premiere of the film.
Also, some film buffs have pointed to Elvis Presley's famous performance of the song "Jailhouse Rock" in MGM's the movie of the same name (often cited as the first music video), released one year after The Girl Can't Help It, as bearing a remarkable resemblance to the theme and performance of a song called "Rock Around the Rockpile" from the earlier movie. In that performance, Edmond O'Brien, seeks to escape an assassination attempt by jumping on stage and singing the lyrics, "rock, rock, rock around the rockpile," while backed up by The Ray Anthony Band wearing striped inmate uniforms. O'Brien, then 42 years old, even awkwardly attempts some of the hip-swiveling and leg motions for which Elvis had already became famous, as he had appeared already 10 times, to cumulative audiences in excess of 180 million viewers, and on national television, before and during the filming of "The Girl Can't help it", the production for which commencing in mid September 1956. Moreover, other film buffs point to the fact that it was the famous acrobatic dancer and Elvis contemporary, as well as MGM star Russ Tamblyn, (Seven Brides for Seven brothers) who visited Elvis at his suite at the Knickerboker Hotel on the night before the filming of the "Jailhouse Rock" scene. He had trouble, that same day at the rehearsals, in interpreting what the MGM choreographer Alex Romero demanded of him, so Tamblyn's input at the suite that night helped Elvis deliver the first of that dancing sequence which, incidentally, was witnessed by none other than the then MGM megastar, Gene Kelly. In fact, the producers had wanted Elvis for The Girl Can't Help It, but Elvis's manager Tom Parker had demanded too much money. Two uncredited composers on The Girl Can't Help It, Hugo Friedhofer and Lionel Newman, had also composed music for the Elvis classic movie, Love Me Tender, in the same year, 1956.
- "The Girl Can't Help It" – Little Richard
- "Tempo's Tempo" – Nino Tempo
- "My Idea of Love" – Johnny Olenn
- "I Ain't Gonna Cry No More" – Johnny Olenn
- "Ready Teddy" – Little Richard
- "She's Got It" – Little Richard
- "Cool It Baby" – Eddie Fontaine
- "Cinnamon Sinner" – Teddy Randazzo and the Three Chuckles
- "Spread the Word" – Abbey Lincoln
- "Cry Me a River" – Julie London
- "Be-Bop-A-Lula" – Gene Vincent and His Blue Caps
- "Twenty Flight Rock" – Eddie Cochran
- "Rock Around the Rockpile" – Edmond O'Brien; Ray Anthony and his Orchestra
- "Rockin' Is Our Business" – The Treniers
- "Big Band Boogie" – Ray Anthony and his Orchestra
- "Blue Monday" – Fats Domino
- "You'll Never, Never Know" – The Platters
- "Ev'ry Time (It Happens)" – Jayne Mansfield (dubbed by Eileen Wilson)
- "Giddy Up a Ding Dong" – Freddy Bell & The Bell-Boys