Anthony Gilbert was the pen name of Lucy Beatrice Malleson (1899–1973), a British author of crime fiction. She also wrote crime fiction as J. Keith and J. Kilmeny Keith, and non-genre fiction as Anne Meredith. She also published one crime novel under the Meredith name.

She published 69 crime novels, 51 of which featured her best known character, Arthur Crook. Crook is a vulgar London lawyer totally (and deliberately) unlike the aristocratic detectives who dominated the mystery field when Gilbert introduced him. Instead of dispassionately analyzing a case, he usually enters a case after seemingly damning evidence has built up against his client, then conducts a no-holds-barred investigation of doubtful ethicality to clear him or her. The first Crook novel was published in 1936 and was immediately popular. The last Crook novel was published in 1974.