Father Brown is a short, plain Roman Catholic priest, with shapeless clothes, a large umbrella, and an uncanny insight into human behaviour.

[2][3] Brown uses his unimposing demeanor to his advantage when studying criminals, to whom he seems to pose no danger, making him a precursor, in some ways, to Agatha Christie's later detective character Miss Marple.

[6] While Brown's cases follow the "Fair Play" rules of classic detective fiction,[2] the crime, once revealed, often turns out to be implausible in its practical details.

[7] A typical Father Brown story aims not so much to invent a believable criminological procedure as to propose a novel paradox with subtle moral and theological implications.

[8] When he created Father Brown, the English writer G. K. Chesterton was already famous in Britain and America for his philosophical and paradox-laden fiction and nonfiction, including the novel The Man Who Was Thursday, the theological work Orthodoxy, several literary studies, and many brief essays.

Father Brown solves his crimes through a strict reasoning process more concerned with spiritual and philosophic truths than with scientific details, making him an almost equal counterbalance to Sir Arthur Conan Doyle's Sherlock Holmes, whose stories Chesterton read.

[6] As Chesterton was already a well-established literary figure before creating Father Brown, the stories' popularity also had a positive impact on detective fiction as a whole, lending the genre further credibility.

[17] Antonio Gramsci, who found the stories "delicious" in their juxtaposition of heightened poetic style and detective-story plotting, argued that Brown was a quintessentially Catholic figure, whose nuanced psychology and moral integrity stand in sharp contrast to "the mechanical thought processes of the Protestants" and make Sherlock Holmes "look like a pretentious little boy".

[18] Kingsley Amis, who called the stories "wonderfully organized puzzles that tell an overlooked truth",[19] argued that they show Chesterton "in top form" as a writer of literary Impressionism, creating "some of the finest, and least regarded descriptive writing of this century":[20] And it is not just description; it is atmosphere, it anticipates and underlines mood and feeling, usually of the more nervous sort, in terms of sky and water and shadow, the eye that sees and the hand that records acting as one.

D. James highlights the stories' "variety of pleasures, including their ingenuity, their wit and intelligence, […] the brilliance of the writing", and especially their insight into "the greatest of all problems, the vagaries of the human heart.

In the novel The D Case by Carlo Fruttero and Franco Lucentini, Father Brown joins forces with other famous fictional detectives to solve Charles Dickens's The Mystery of Edwin Drood.