Which mystery writer used the pseudonym 'Mary Westmacott'?

The mystery writer who used the pseudonym Mary Westmacott was Agatha Christie. Christie published six mainstream, non-detective novels under that name between 1930 and 1956, allowing her to explore family relationships, emotional conflict, and psychological themes outside the mysteries associated with Hercule Poirot and Miss Marple.

The first Westmacott novel was Giant’s Bread, published in 1930. The books were written as serious mainstream fiction rather than conventional detective stories, and several received strong reviews. Christie later explained that the pseudonym gave her freedom to write about what she described as a more private imaginative world.

Christie’s identity was initially kept secret, although readers knew Mary Westmacott was a pen name belonging to an established author. A journalist revealed the connection in 1949, after which Christie continued using the pseudonym for two further novels. The name is therefore not a separate writer, but one of Christie’s literary identities.