A Series of Unfortunate Events is a children's book series of thirteen novels written by Lemony Snicket, and illustrated by Brett Helquist. It is about the adventures of three children, the Baudelaire orphans, after the death of their parents in a fire. The setting of the series is anachronistic, and throughout the series there are many literary and cultural allusions. A film adaptation of the first three books in the series was released on December 17, 2004, as Lemony Snicket's A Series of Unfortunate Events,which also had a video game adaptation of the same name based on it.Audio books have been released which included songs by The Gothic Archies, and a compilation album of the songs has also been released.

The series follows the adventures of three siblings, Violet, Klaus and Sunny Baudelaire, after their parents were killed in a fire at the family mansion. In The Bad Beginning, they briefly live with a friend of their parents, Mr. Poe, who is the person in charge of the Baudelaire fortune after the Baudelaire parents' deaths, before being sent to live with Count Olaf, whom Mr. Poe describes as either the siblings' "third cousin four times removed, or their fourth cousin three times removed". The siblings discover that he intends to get his hands on the enourmous Baudelaire fortune, which awaits Violet, the eldest child, when she turns eighteen.[5] In the first seven books, Olaf, each time in different disguises, follows the children wherever they go so he can get closer to the orphans and steal their fortune. Their roles switch in the eighth through twelfth books, in which the orphans adopt disguises while on the run from the police after being framed by Count Olaf, disguised as Detective Dupin, for the murder of Count Omar (really Jacques Snicket). The Baudelaires routinely try to get help from Mr. Poe, but Poe is always either busy with work, oblivious to the danger Olaf poses, unaware that the disguised Olaf is not who he claims to be or simply thinks the Baudelaires are lying.

Each of the three siblings has a distinctive skill that often helps them during their adventures. Violet is always inventing new things to help them, Klaus is always finding out new information by reading books, and Sunny has extremely sharp teeth that can bite almost anything in half.In later books, Sunny learns how to cook, as she begins to grow to the normal size for her teeth so cooking becomes her primary skill. Sunny originally spoke in single word utterances which are often a variety of incomplete sentences, and some short word sentences as well. Their meaning is either disguised by being spelled phonetically (e.g., 'surchmi' in The Slippery Slope), backwards (e.g., 'edasurc' [crusade] in The Carnivorous Carnival) through cultural references (Sunny says: 'Matahari', followed by a definition of 'If I stay, I can spy on them and find out.'), or being written in other languages (e.g., Shalom or Sayonara), but eventually she begins to speak more in complete English sentences, her first possibly being "I'm not a baby" in The Slippery Slope,or "Like me" in The Vile Village.

Lemony Snicket, the author of the stories and the pseudonym of Daniel Handler, is actually a character himself on the periphery of the stories. He follows the Baudelaires, researching and recording their exploits. Bruce Butt noted in 2002 that in each book a letter from Snicket to his editor is included, presented as exciting updates on Snicket's research into the Baudelaire orphans, which Butt considered to be "the most sly aspect of the way this series has been ingeniously promoted".Over the course of the series, the Baudelaires learn some vague information about Snicket and possibly meet him briefly in The Wide Window and The Penultimate Peril.