The book follows events in the life of a concierge, Renée Michel, whose deliberately concealed intelligence is uncovered by an unstable but intellectually precocious girl named Paloma Josse.

Featuring a number of erudite characters, The Elegance of the Hedgehog is full of allusions to literary works, music, films, and paintings.

In the case of Paloma, the narration takes the form of her written journal entries and other philosophical reflections; Renée's story is also told in the first person but more novelistically and in the present tense.

The story revolves mainly around the characters of Renée Michel and Paloma Josse, residents of an upper-middle class Left Bank apartment building at 7 Rue de Grenelle – one of the most elegant streets in Paris.

Her perspective is that "[t]o be poor, ugly and, moreover, intelligent condemns one, in our society, to a dark and disillusioned life, a condition one ought to accept at an early age".

Dismayed by the privileged people around her, she decides that life is meaningless, and that unless she can find something worth living for, beyond the "vacuousness of bourgeois existence",[2] she will commit suicide on 16 June, her thirteenth birthday.

Paloma is the only tenant who suspects Renée's refinement, and for most of the novel, the two "cross each other but don't see each other", in the words of Time Out reviewer Elisabeth Vincentelli.

[5] Toward the end of the novel, Renée comes out of her internal seclusion, teaching young Paloma that not all adults pursue vanity at the expense of their intelligence and humanity.

[6] Renée, however is self-taught; she reads works of the German philosopher Immanuel Kant and Russian writer Leo Tolstoy (and even names her cat "Leo"), disdains the philosophy of Edmund Husserl, adores 17th-century Dutch paintings, likes Japanese art-house films by Yasujirō Ozu, and listens to the music of composers Henry Purcell and Gustav Mahler.

[7][8] Renée, who conceals her true self to conform to the lowly image of typical concierges, introduces herself as "a widow, short, ugly, chubby", with "bunions on my feet and, on certain difficult mornings, it seems, the breath of a mammoth".

Other characters developed by Barbery in the novel include Kakuro Ozu, the cultured Japanese businessman, and Manuela, a Portuguese cleaner.

[11] Most critics considered Barbery's narrative presentation to be essayistic; the individual chapters are more akin to essays than fiction, as The New York Times' Caryn James expresses it, "so carefully build[ing] in explanations for the literary and philosophical references that she seems to be assessing what a mass audience needs".

[5] Barbery confesses to having "followed a long, boring course of studies in philosophy", and comments that "I expected it to help me understand better that which surrounds me: but it didn't work out that way.

That's where the desire to anchor philosophy to a story, a work of fiction, was born: to give it more meaning, make it more physically real, and render it, perhaps, even entertaining.

[5][16] Novelist Alison Anderson translated L'Élégance du hérisson into English as The Elegance of the Hedgehog, and this version was released in September 2008 by Europa Editions.

[11] According to reviewer Viv Groskop, the philosophical element in the novel partly explains its appeal in France, where philosophy remains a compulsory subject.

In the earliest known review, for the Italian newspaper La Repubblica, Maurizio Bono writes that "[t]he formula that made more than half a million readers in France fall in love with [The Elegance of the Hedgehog] has, among other ingredients: intelligent humor, fine sentiments, an excellent literary and philosophical backdrop, taste that is sophisticated but substantial".

[9] Praising the novel in his review for The Guardian, Ian Samson wrote that "The Elegance of the Hedgehog aspires to be great and pretends to philosophy: it is, at least, charming.

"[8] In an earlier review in the same paper, Groskop opined that the novel is a "profound but accessible book ... which elegantly treads the line between literary and commercial fiction".

[23] Caryn James of The New York Times hailed the novel as "studied yet appealing commercial hit", adding that it "belongs to a distinct subgenre: the accessible book that flatters readers with its intellectual veneer".

[7] Los Angeles Times' Susan Salter Reynolds wrote that "[The Elegance of the Hedgehog] is a high-wire performance; its characters teeter on the surreal edge of normalcy.