A young woman has difficulty understanding why her husband walks out on her. Alone for the first time, she finds life difficult to cope with and for a time lives with the hope that her husband will come back to her.
Unfortunately the movie One Is a Lonely Number is not yet available on HBO Max.
| Directing | Mel Stuart | Director |
| Writing | David Seltzer | Screenplay |
| Writing | Rebecca Morris | Story |
| Art | Douglas Freeman | Set Dresser |
| Art | Frank Wesselhoff | Painter |
| Sound | Bud Alper | Sound |
| Sound | Hal Watkins | Sound |
| Camera | Sherman Kunkel | Camera Operator |
| Costume & Make-Up | Dina Joseph | Wardrobe Master |
| Editing | James T. Heckert | Associate Editor |
| Crew | Eileen Peterson | Unit Publicist |
| Sound | Michel Legrand | Conductor |
| Production | Stan Margulies | Producer |
| Production | David L. Wolper | Executive Producer |
| Sound | Michel Legrand | Original Music Composer |
| Camera | Michel Hugo | Director of Photography |
| Editing | David Saxon | Editor |
| Production | Hoyt Bowers | Casting |
| Art | Walter M. Simonds | Art Direction |
| Art | George Gaines | Set Decoration |
| Production | John W. Rogers | Unit Production Manager |
| Directing | Donald C. Klune | Assistant Director |
| Art | Stephen R. Ferry | Property Master |
