 | Tony Curtis als Joe / Josephine |
 | Jack Lemmon als Jerry / Daphne |
 | Marilyn Monroe als Sugar Kane Kowalczyk |
 | George Raft als Spats Colombo |
 | Pat O’Brien als Detective Mulligan |
 | Joe E. Brown als Osgood Fielding III |
 | Nehemiah Persoff als Little Bonaparte |
 | Joan Shawlee als Sweet Sue |
 | Billy Gray als Sig Poliakoff |
 | George E. Stone als Toothpick Charlie |
 | Dave Barry als Beinstock |
 | Mike Mazurki als Spats' Henchman |
 | Harry Wilson als Spats' Henchman |
 | Beverly Wills als Dolores |
| Barbara Drew als Nellie |
 | Edward G. Robinson Jr. als Johnny Paradise |
| Sam Bagley als Minor Role (uncredited) |
| Alex Ball als Speakeasy Patron (uncredited) |
| Brandon Beach als Party Guest (uncredited) |
| Phil Bloom als Gangster at Convention (uncredited) |
| Willie Bloom als Gangster at Convention (uncredited) |
| Al Breneman als Bellhop (uncredited) |
 | Steve Carruthers als Hotel Guest (uncredited) |
| James J. Casino als Gangster at Convention (uncredited) |
 | Noble 'Kid' Chissell als Police Officer (uncredited) |
| Beulah Christian als Speakeasy Patron (uncredited) |
| Ted Christy als Gangster (uncredited) |
| Robert Cole als Club Patron (uncredited) |
 | Marian Collier als Olga (uncredited) |
| Pat Comiskey als Spats' Henchman (uncredited) |
| Bing Conley als Gangster at Convention (uncredited) |
| Paul Cristo als Gangster at Convention (uncredited) |
 | James Dime als Gangster Convention Greeter (uncredited) |
 | Franklyn Farnum als Party Guest (uncredited) |
| Duke Fishman als Gangster at Convention (uncredited) |
| Mary Foley als Band Member (uncredited) |
| George Ford als Police Officer (uncredited) |
 | Paul Frees als Funeral Director / Waiter / Josephine (voice) (uncredited) |
| Bobby Gilbert als Speakeasy Patron (uncredited) |
| Joseph Glick als Gangster at Convention (uncredited) |
| Jack Gordon als Gangster with Charlie (uncredited) |
| Joe Gray als Mobster at Banquet (uncredited) |
| Stuart Hall als Speakeasy Patron (uncredited) |
| Sam Harris als Hotel Guest (uncredited) |
| Harold 'Tommy' Hart als Official #2 (uncredited) |
| William Hoehne Jr. als Policeman (uncredited) |
 | Shep Houghton als Speakeasy Patron (uncredited) |
| John Indrisano als Waiter (uncredited) |
 | Tom Kennedy als Bouncer (uncredited) |
| Joseph La Cava als Gangster at Convention (uncredited) |
| George Lake als Small Role (uncredited) |
 | Carl M. Leviness als Retirement Home Resident (uncredited) |
| King Lockwood als Gangster at Convention (uncredited) |
 | Hank Mann als Speakeasy Patron (uncredited) |
| Tiger Joe Marsh als Small Role (uncredited) |
 | Jack Mather als Small Role (uncredited) |
| Tipp McClure als Spats' Henchman (uncredited) |
 | Frank McLure als Speakeasy Patron (uncredited) |
 | Laurie Mitchell als Mary Lou (uncredited) |
 | William H. O'Brien als Hotel Guest (uncredited) |
| Colleen O'Sullivan als Band Member (uncredited) |
| Joe Palma als Small Role (uncredited) |
| Helen Perry als Rosella (uncredited) |
 | Jack Perry als Gangster at Convention (uncredited) |
| Danny Richards Jr. als Fresh Bellboy (uncredited) |
| Edwin Rochelle als Chef (uncredited) |
| John Roy als Police Officer (uncredited) |
| Cosmo Sardo als Waiter (uncredited) |
 | Scott Seaton als Old Man (uncredited) |
| Sammy Shack als Commuter at Station (uncredited) |
 | Fred Sherman als Drunk (uncredited) |
 | Carl Sklover als Small Role (uncredited) |
 | Bert Stevens als Speakeasy Patron (uncredited) |
 | Arthur Tovey als Speakeasy Patron (uncredited) |
| Sid Troy als Gangster at Convention (uncredited) |
| Ralph Volkie als Gangster at Massacre (uncredited) |
 | Tito Vuolo als Mozzarella (uncredited) |
 | Sandra Warner als Emily (uncredited) |
 | Billy Wayne als Small Role (uncredited) |
 | Grace Lee Whitney als Rosella (uncredited) |
| Georgia Joan Hannan als Band Member (uncredited) |
| Billy Wilder | Director |
| Charles Lang | Director of Photography |
| Billy Wilder | Producer |
| Doane Harrison | Producer |
| Arthur P. Schmidt | Editor |
| Robert Thoeren | Story |
| Eve Newman | Music Editor |
| Billy Wilder | Screenplay |
| Adolph Deutsch | Original Music Composer |
| Phil Benjamin | Casting |
| Ted Haworth | Art Direction |
| Edward G. Boyle | Set Decoration |
| Agnes Flanagan | Hairstylist |
| Emile LaVigne | Makeup Artist |
| Alice Monte | Hairstylist |
| Allan Snyder | Makeup Artist |
| Allen K. Wood | Production Manager |
| Hal W. Polaire | Assistant Director |
| Fred Lau | Sound |
| Milt Rice | Special Effects |
| Daniel Hays | Special Effects |
| Paul Baxley | Stunts |
| Polly Burson | Stunts |
| Joe Gray | Stunts |
| Carey Loftin | Stunts |
| Bernie Abramson | Still Photographer |
| Phil Stern | Still Photographer |
| Don Stott | Gaffer |
| Gerald Wiggins | Vocal Coach |
| John Franco | Script |
| Jack Cole | Choreographer |
| John Veitch | Location Manager |
| Matty Malneck | Songs |
| Matty Malneck | Music |
| Sam Nelson | Assistant Director |
| Barney Kessel | Additional Soundtrack |
| Michael Logan | Story |
| I. A. L. Diamond | Associate Producer |
| I. A. L. Diamond | Screenplay |
| Bert Henrikson | Wardrobe Supervisor |
| Doane Harrison | Associate Producer |
| Tom Plews | Props |
| Orry-Kelly | Costume Design |
