 Jascha HeifetzHimself | Himself |
 Joel McCreaPeter McCarthy | Peter McCarthy |
 Andrea LeedsAnn Lawson | Ann Lawson |
 Gene ReynoldsFrankie | Frankie |
 Walter BrennanProfessor Lawson | Professor Lawson |
 Terry KilburnLimey | Limey |
 Tommy KellyWillie | Willie |
 Porter HallMr. Flower | Mr. Flower |
 Walter TetleyRocks Mulligan | Rocks Mulligan |
| CChuck StubbsFever | Fever |
 Gale SherwoodBetty | Betty |
 Alfred NewmanMusical Director | Musical Director |
| MMary RuthSuzie | Suzie |
 John St. PolisDavis | Davis |
| AAlexander SchoenbergMenken | Menken |
 Marjorie MainMrs. Miller | Mrs. Miller |
 Arthur HohlMiller | Miller |
 Paul HarveyHeifetz' Manager | Heifetz' Manager |
| ZZeroSucker the Dog | Sucker the Dog |
| PPeter MeremblumPeter Meremblum | Peter Meremblum |
| CCalvin Leslie(uncredited) | (uncredited) |
| EEffie AndersonWoman on Steps (uncredited) | Woman on Steps (uncredited) |
 Jessie ArnoldWoman in Alley Yelling for Police (uncredited) | Woman in Alley Yelling for Police (uncredited) |
 Arthur AylesworthDetective (uncredited) | Detective (uncredited) |
| EEmanuel BayAccompanist for 'Hora staccato' (uncredited) | Accompanist for 'Hora staccato' (uncredited) |
 Brooks BenedictMan in Concert Audience (uncredited) | Man in Concert Audience (uncredited) |
| RRichard BerresCellist in Meremblum Orchestra (uncredited) | Cellist in Meremblum Orchestra (uncredited) |
 Stanley BlystonePoliceman at Police Station (uncredited) | Policeman at Police Station (uncredited) |
| MMorris BoltuchKid in Orchestra (uncredited) | Kid in Orchestra (uncredited) |
 Wade BotelerBill - Police Lieutenant (uncredited) | Bill - Police Lieutenant (uncredited) |
