Death in Fancy Dress is a 1933 mystery detective novel by the British writer Anthony Gilbert, the pen name of Lucy Beatrice Malleson.

[1] It was republished in 2019 by British Library Publishing as part of a series featuring traditional crime novels.

It takes the form of a country house mystery, a popular branch of the genre during the era.

A notorious blackmailer is haunting London Society, leading to several suicides.

The Home Office's attempt to capture them leads to a fancy dress ball at the country estate Feltham Abbey, where things come to a head when the host Sir Ralph Feltham is found dead in the grounds.