Mr Pye is described as "an extremely ladylike plump little man". His main enjoyment in life is taking people around his house, which is exquisite, with every piece of furniture polished and set in exactly the right place. Jerry Burton feels that living there would be like "taking up one's abode in a period room at a museum".
Mr Pye likes Jerry and Joanna Burton, as they are both fond of antiquities and period furniture. He feels that most people in Lymstock are bucolic and provincial, and that they surround themselves with ugliness, when beauty is the only thing worth living for.
Mr Pye is a brilliant bridge-player, and has "an uncanny flair for psychic bidding".
The police suspect that the person writing the anonymous letters in Lymstock is a woman. However, Joanna considers Mr Pye a possible suspect, pointing out that he might be lonely, unhappy, and spiteful, because everyone rather laughs at him. When Jerry points out that the police are lookijg for a middle-aged spinster, Joanna says that Mr Pye is a middle-aged spinster.
In the BBC 1985 adaptation of the novel which formed part of the Miss Marple series, Mr Pye is played by Richard Pearson. He finds Lymston dull but says he fled to the village for sanctuary because he was frightened of the bombing of London during the Second World War. He used to run an antique in the King's Road, Chelsea.
In the ITV 2006 adaptation of the novel (Episode 2, Series of Agatha Christie's Marple), Pye is played by John Sessions. Here he is given the firstname "Cardew" which is not used in the original novel.