She was portrayed by Lyndsey Marshal in Agatha Christie's Poirot.
Anne Meredith once worked for an elderly woman named Mrs. Benson, whom she stole from in secret. However, one day, Mrs. Benson discovered Meredith's crime, so Meredith killed her employer and escaped, faking it to be an accidental poisoning.
Meredith joined the invitation of Shaitana and showed her admirations towards Poirot and Mrs. Ariadne Oliver, before she started to play cards with other three guests. After Shaitana was killed by one of the guests, Meredith became a suspect because of her past of alledged poisoning of her employer. During the investigation, Meredith became extremely paranoid.
The next morning, in the meantime when Mrs. Lorrimer was found dead, Meredith decided to take her flatmate, Rhoda Dawes, for a punt in the nearby river, as they await a visit from John Despard. However, Meredith decided to drown her friend to silence her. During the struggle, both of them fell into the water just in time when Poirot and Superintendent Battle arrived, suspecting that another murder was taking place. Despard, Poirot and Battle managed to save Rhoda's life, but Meredith was drowned. Her crime was later revealed during the denouement.
- Meredith made several references of the novel's main characters in the story. In chapter 2, she said she heard about Poirot once he solved the case of the ABC Killer. She also said she knew about Mrs. Oliver after reading a book she wrote, titled The Body in the Library.
- Fun fact: The Body in the Library is the same title to a later novel of Agatha Christie herself, which was first published in 1942 and featured Miss Marple as its protagonist.
- In Agatha Christie's Poirot, Meredith didn't die and was not as murderous as the original novel. Her role of murderous side and her death was switched with Rhoda Dawes, who was adapted into a psychotic and implied lesbian. In Agatha Christie's Poirot, it was Rhoda who killed Mrs. Benson and had unhealthy obsession towards Meredith, rather than the other way round.
- In the original novel, Rhoda was innocent of the murder and later married John Despard, before returning in The Pale Horse as a supporting character.
- Also in Agatha Christie's Poirot, Meredith was the estranged daughter of Mrs. Lorrimer, who intended to cover up her daughter's murder suspicion and take the blame for Shaitana's death. This never appeared in the novel.