Ariadne Oliver is a fictional mystery novelist and friend of Hercule Poirot, created by Agatha Christie.
The first appearance of Ariadne Oliver was in the short story "The Case of the Discontented Soldier" which was first published, along with four other stories in the August 1932 issue of the US version of Cosmopolitan magazine. The story first appeared in the UK in Woman's Pictorial on 15 October 1932, and was later published in book form in 1934 as Parker Pyne Investigates (titled Mr. Parker Pyne, Detective in the USA). Within this story she appeared as part of Pyne's unorthodox team of freelance assistants. Within the same book, she also briefly appears in "The Case of the Rich Woman".
All her subsequent appearances (except The Pale Horse) were in Poirot novels:
Cards on the Table (1936)
Mrs McGinty's Dead (1952)
Dead Man's Folly (1956)
The Pale Horse (1961) – Oliver's only appearance in a Christie novel without Poirot
Third Girl (1966)
Hallowe'en Party (1969)
Elephants Can Remember (1972)
Hercule Poirot and the Greenshore Folly (2014) – a novella that was later expanded and published as Dead Man's Folly.