The Man Who Knew Too Much and other stories (1922) is a book of detective stories by English writer G. K. Chesterton, published in 1922 by Cassell and Company in the United Kingdom, and Harper Brothers in the United States. The book contains eight connected short stories about "The Man Who Knew Too Much", and additional unconnected stories featuring separate heroes/detectives. The United States edition contained one of these additional stories: "The Trees of Pride", while the United Kingdom edition contained "Trees of Pride" and three more, shorter stories: "The Garden of Smoke", "The Five of Swords" and "The Tower of Treason".

Horne Fisher, "The Man Who Knew Too Much", is the main protagonist of the first eight stories. In the final story, "The Vengeance of the Statue", Fisher notes: "The Prime Minister is my father's friend. The Foreign Minister married my sister. The Chancellor of the Exchequer is my first cousin." Because of these intimate relationships with the leading political figures in the land, Fisher knows too much about the private politics behind the public politics of the day. This knowledge is a burden to him in the eight stories, because he is able to uncover the injustices and corruptions of the murders in each story, but in most cases the real killer gets away with the killing because to bring him openly to justice would create a greater chaos: starting a war, reinciting Irish rebellions or removing public faith in the government.

In the seventh story, "The Fad of the Fisherman", the Prime Minister himself is the murderer, who kills the financier whose country house he is visiting because the financier is trying to start a war with Sweden over "the Danish ports". By killing his host, the Prime Minister seeks to avoid a war in which many more people would die, and the financier would profit at the cost of thousands of lives.

Fisher is accompanied in the stories by a political journalist, Harold March, but rather than being his "Watson", the stories are all written in the third person. Less a clumsy foil to reflect Fisher's brilliance, March is more of a sounding board for Fisher to discuss Chesterton's paradoxes and philosophy. Apart from the first story, in which March meets Fisher, and the final story, the stories have no internal chronology, and so can be read in any order.

Contents    
The face in the target -- The vanishing prince -- The soul of the schoolboy -- The bottomless well -- The hole in the wall -- The fad of the fisherman -- The hole in the wall -- The temple of silence -- The vengeance of the statue.