Lost Illusions is a novel from the series The Human Comedy by a great French writer Honoré de Balzac. It is the longest novel in this series.

The novel contains four parts, which actions happen during the Restoration times.

It was first planned as a story about deluded with each other poet and woman from provincial high society, who, after moving to Paris, in a pitiless and real world saw what they actually represented by themselves, and separated.

But when the story was written, it turned out to be only an introduction to a novel. The action of the novel takes place in 1819–1823 and blends seamlessly into these years, it is mainly motivated by the history of France. Every character of Lost Illusions appears in the novel from the past of their country, their family and something of their own.