The film is the story of Tony Wendice (Ray Milland), a former tennis player married to the beautiful and wealthy Margot (Grace Kelly) for her money and living in a nice apartment in London. Life is good for Tony, until he discovers that his wife seems to have an affair with Mark (Robert Cummings), an American writer. Tony is afraid that she will ask him for divorce in order to marry Mark. Margot had a brief affair with Mark, but decided to remain loyal, despite her love for Mark, and is not aware of the fact that her husband already knows about her past relationship with Mark, who happens to visit them when Tony decides he has to arrange the death of his wife so that he might inherit her fortune. Tony blackmails a former acquaintance, Captain Lesgate (Anthony Dawson), who has embarked on a life of petty crime into murdering Margot and making her death look like the work of a burglar. Lesgate cannot refuse. Tony has gathered enough information to turn him over to the police. But the plan goes awry when Margot manages to fight back and kill her assailant in self-defense. When the police investigate, Tony improvises quickly, implicating her as being guilty of premeditated murder. The evidence all points to Margot as a first degree murderess. Margot is convicted and sentenced to be hanged.

  The performances are fine. Grace Kelly is at her loveliest, she is amazing, the same year she made Rear Window with Hitchcock. Ray Milland delivers one of his finest portrayals, and gives the character, completely understating his menace and evil intentions, a softness and vulnerability.

 Dial M for Murder was remade in 1998 as A Perfect Murder directed by Andrew Davis and starring Michael Douglas and Gwyneth Paltrow.

 Everyone on the Hitchcock set fell in love with Grace, including the director, but none fell harder than her leading man. During the making of the film, Milland attempted to seduce Grace. He was married to Muriel Milland for thirty years, and the two had a son. Milland assured Kelly that he had left his wife, which she would later find out to have been a lie.

 In 2008, the American Film Institute revealed its Ten top Ten — the best ten films in ten classic American film genres — after polling over 1,500 people from the creative community. Dial M for Murder was acknowledged as the ninth best film in the mystery genre. Grace Kelly was named Best Actress by the National Board of Review and the New York Film Critics Circle for the role in the film.