Inspector Gabriel Hanaud is a fictional character depicted in a series of novels and short stories by the British writer A. E. W. Mason. He has been described as the "first major fiction police detective of the Twentieth Century".
He was modelled on two real-life heads of the Paris Sûreté, Macé and Goron. Émile Gaboriau's Monsieur Lecoq was also an acknowledged inspiration. Mason wanted to physically differentiate Hanaud from Sherlock Holmes as much as possible, and so he made him stout and broad-shouldered in contrast to Holmes who was thin. He often relies on psychological methods to solve cases. Hanaud is assisted by his friend, the fastidious Mr Julius Ricardo, a former City of London financier.
Hanaud makes his first appearance in the 1910 story At the Villa Rose set in the south of France. He appeared in a further four novels, and several short stories. His last appearance was in the 1946 novel The House in Lordship Lane. Hanaud was portrayed on screen several times – with adaptations of At the Villa Rose and its sequel The House of the Arrow
He has been seen as one of a number of influences on the creation of Agatha Christie's Belgian detective Hercule Poirot.