Leona Stevenson (Stanwyck) is a bedridden, hypochondriac heiress. While on the phone trying to find out where her husband Henry (Lancaster) is on a hot New York night, she accidentally overhears a conversation about a planned murder.
Panicking, Leona starts calling friends and family to trace Henry's steps, only to discover mounting evidence that he himself may be involved with the murder.
Sorry, Wrong Number provides examples of:
- Adaptation Expansion: Screenwriter Lucille Fletcher adapted her own 22-minute radio play of the same name, which was famous as a tour de force vehicle for Agnes Moorehead (who performed it eight different times on Suspense between 1943 and 1960). The film expands the plot by allowing the audience to be privy to the other side of Leona's increasingly frantic telephone calls, and using a series of flashbacks to detail the set of circumstances that led up to the murder being planned.
- Awful Wedded Life: Leona and Henry's marriage is a sham. Highlighted with a shot of their separate beds in separate rooms living situation.
- Bottle Episode: Except for the flashbacks, the film takes place in Leona's apartment.
- Cacophony Cover-Up: George is told to commit the murder as the train is going by the apartment, so that if the victim screams, she won't be heard through the open window.
- Creator Cameo: Where Henry is having lunch with Sally, he asks his waiter if he knows who the gentleman is in the dark glasses at the table behind him. The man is director Anatole Litvak.
- Downer Ending: Leona is murdered, and Henry is arrested for theft.
- Exact Eavesdropping: Leona overhears on the phone two men talking about a planned murder, but they can't hear her.
- Faux Affably Evil: The gangster Morano seems very affable and chummy as he is describing to Henry how he can extract himself from the mess he is in, until you realise that he is telling Henry to murder his wife.
- Flashback: As Leona learns about what Henry's been up to, there are various flashbacks of other characters and their interactions with him.
- The Film of the Play: Radio play to be specific.
- Flashback Within a Flashback: Dr. Alexander's flashback about his conversation with Henry about Leona's heart condition segues into a flashback of Henry discussing his marriage.
- Henpecked Husband: Henry is bursting at the seams because he feels like he has no control over his life. He wants to make his own living but Leona and her father won't let him. So, he turns to reckless crime and eventually plans Leona's murder.
- Idle Rich: Leona is born into wealth and loves it. Henry, on the other hand, is stifled under her controlling behaviour.
- Laser-Guided Karma: Henry is being arrested right after Leona is murdered.
- Obfuscating Disability: The only reason Henry has stayed so long with Leona (even though he's clearly unhappy) is her heart condition. Once he finds out that her condition has only been in her head, it's the catalyst to him planning her murder.
- Obnoxious In-Laws: Not only is Leona overbearing, but her father is too, managing to outmanoeuvre Henry whenever he tries to make a name for himself.
- Oh, Crap!: In the final phone call between Henry and Leona, they both get the expressions of people who know they're irrevocably doomed:
- Henry thinks he's just calling Leona to distract her while George comes upstairs to kill her, but when she tells him about her conversation with Evans, particularly the fact that Morano has been arrested (and is implied to be singing like a canary to the DA's office about Henry's role in the ongoing theft), his expression almost immediately shifts from cold and calculating to horrified alarm, as he knows it's only a matter of time before the police catch up with him (indeed, it's already happened; a uniformed policeman and a plainclothes detective speak on the train platform behind him before the latter opens the phone booth door to arrest Henry).
- Now aware that his scheme to have her murdered will achieve nothing besides additional criminal charges, Henry tries to get Leona to go to the window and scream to alert the neighbours, but as her heart condition is psychosomatic, she cannot move from her bed out of fear, which escalates to full-blown panic when she sees George's shadow coming up the stairs; she knows she has seconds to live and cannot do anything about it.
- The Perfect Crime: Henry concocts a plan to steal from Leona's father, but it fails miserably. It seems, however, that his plan to murder Leona came off without a hitch.
- Plot Twist: It was Henry who planned Leona's murder so that he could use her life insurance money to pay off Morano.
- Real Time: The film unfolds in real time, as can be seen by the clock on Leona's bedside table.
- "Rear Window" Witness: A crossed line causes an invalid to overhear two people planning to kill her.
- Title Drop: The last line of the film is George's voice saying "Sorry, wrong number" before the handset is placed back on the receiver.
- Unexplained Accent: Ann Richards' character Sally Hunt-Lord is supposedly from a working class town in Illinois, but speaks with a 'Received Pronunciation' English accent. As Richards was born in Australia to an American father and a New Zealander mother, it's not her native accent either. It might be an affectation she adopted when she went to college, but is never explained.
- Uptown Girl: Leona is obscenely wealthy and sets her eyes on working class Henry. Henry only married Leona for the financial escape she offered.
- Wham Line: Also, a Title Drop as Leona's murderer answers Henry's call and says the title.