Molly and Terry Donahue, plus their three children, are The Five Donahues. Youngest son Tim meets hat-check girl Vicky and the family act begins to fall apart.
| Actor | Role |
|---|---|
 Ethel MermanMolly Donahue | Molly Donahue |
 Marilyn MonroeVicky | Vicky |
 Mitzi GaynorKaty Donahue | Katy Donahue |
 Dan DaileyTerence Donahue | Terence Donahue |
 Donald O'ConnorTim Donahue | Tim Donahue |
 Johnnie RaySteve Donahue | Steve Donahue |
 Richard EasthamLew Harris | Lew Harris |
 Hugh O'BrianCharles Gibbs | Charles Gibbs |
 Frank McHughEddie Dugan | Eddie Dugan |
 Rhys WilliamsFather Dineen | Father Dineen |
 Lee PatrickMarge | Marge |
 Eve MillerHelen | Helen |
 Dorothy AbbottShowgirl (uncredited) | Showgirl (uncredited) |
 Lyle TalbotStage Manager (uncredited) | Stage Manager (uncredited) |
 George ChakirisDancer (uncredited) | Dancer (uncredited) |
 John DoucetteStage Manager (uncredited) | Stage Manager (uncredited) |
 Alvy MooreKaty's Date (uncredited) | Katy's Date (uncredited) |
| RRon NymanTattooed Sailor (uncredited) | Tattooed Sailor (uncredited) |
 Walter WinchellWalter Winchell (voice) (uncredited) | Walter Winchell (voice) (uncredited) |
 Dorothy AdamsNurse (uncredited) | Nurse (uncredited) |
 Robin RaymondLillian Sawyer (uncredited) | Lillian Sawyer (uncredited) |