Charlotte Clarke

Lady Charlotte Clarke is the widow of Sir Carmichael Clarke in the novel The A.B.C. Murders. She is dying of cancer and takes various drugs, her condition also makes her delusional and irritated. However, she provides a vital clue to Poirot by insisting that a stranger had come to the house and had spoken to Thora Grey, a secretary whom she disliked on the day her husband was murdered.

Portrayals
In the MGM adaptation The Alphabet Murders (1965), the character's name is changed Lady Diane Clarke. Here, she is considerably younger and far from being an invalid. She has an affair with the psychiatrist Duncan Doncaster but is found out by her husband. Later, after the death of Sir Carmichael, she is seen heading north on a train to Scotland with Franklin Clarke. Supposedly they are taking her late husband's body on board a ship for burial at sea and thereafter, the two of them were to go to South America for a rest cure. On the train, she celebrates her newly inherited fortune over a glass of champagne with Franklin. She wasn't to know that her champagne had been poisoned by Franklin who had other plans. The part of Lady Diane is played by Sheila Allen.

In the anime show ABC Murders, NHK's adaptation of The A.B.C. Murders, the character of Lady Clarke also makes an appearance in a portrayal that is very close to that in the original novel. The voice actress behind the character is not credited.

In the film adaptation of The A.B.C. Murders in Series 2 of ITV's Agatha Christie's Poirot, the part of Lady Clarke is played by Vivienne Burgess.

In the 2018 BBC mini series The ABC Murders she was played by Tara Fitzgerald.