Tacey and Harry King are a suburban couple with three sons and a serious need of a babysitter. Tacey puts an ad in the paper for a live-in babysitter, and the ad is answered by Lynn Belvedere. But when she arrives, she turns out to be a man. And not just any man, but a most eccentric, outrageously forthright genius with seemingly a million careers and experiences behind him.
| Writing | Gwen Davenport | Novel |
| Directing | Walter Lang | Director |
| Writing | F. Hugh Herbert | Screenplay |
| Art | Ernest Lansing | Set Decoration |
| Costume & Make-Up | Ben Nye | Makeup Artist |
| Production | Darryl F. Zanuck | Executive Producer |
| Art | Lyle R. Wheeler | Art Direction |
| Production | Samuel G. Engel | Producer |
| Camera | Norbert Brodine | Director of Photography |
| Art | Thomas Little | Set Decoration |
| Costume & Make-Up | Kay Nelson | Costume Design |
| Art | Leland Fuller | Art Direction |
| Sound | Alfred Newman | Original Music Composer |
| Editing | Noel L. Scott | Editor |
| Editing | J. Watson Webb Jr. | Editor |
| Production | Max Golden | Production Manager |
| Directing | Gaston Glass | Assistant Director |
| Sound | Roger Heman Sr. | Sound |
| Sound | George Leverett | Sound |
| Crew | Fred Sersen | Special Effects |
| Camera | Leo McCreary | Grip |
| Camera | Irving Rosenberg | Camera Operator |
| Camera | Emmett Schoenbaum | Still Photographer |
| Costume & Make-Up | Charles LeMaire | Wardrobe Master |
| Costume & Make-Up | Sam Benson | Wardrobe Supervisor |
| Editing | Harmon Jones | Editorial Consultant |
| Sound | Lyman Hallowell | Apprentice Sound Editor |
| Directing | Jerry Bryan | Script Supervisor |
| Crew | Hugh Cummings | Dialogue Coach |
| Sound | Edward B. Powell | Orchestrator |
| Crew | Earle Hagen | Additional Music |
| Sound | Charles Henderson | Other |
