Little Dorrit is a sprawling satirical novel that critiques the shortcomings of British society and government institutions, particularly the debtors' prison system and the stifling nature of social class.

The story centers on Amy Dorrit, affectionately known as Little Dorrit, who is born and raised in the Marshalsea debtors' prison in London, where her father, William Dorrit, has been imprisoned for many years. Despite the bleak surroundings, Amy maintains a kind, selfless, and industrious nature, working as a seamstress to support herself and her family within the prison walls.

Arthur Clennam, a man returning to London after years abroad, becomes intrigued by Amy and her family's plight. He suspects his own family may have played a role in the Dorrits' misfortune and seeks to uncover the truth and help them. His investigations lead him through various strata of London society, from the impoverished to the wealthy, and expose the hypocrisy and inefficiency of institutions like the Circumlocution Office – a fictional government department renowned for its bureaucratic red tape and inability to get anything done.

A significant turn of events occurs when William Dorrit inherits a substantial fortune, leading to the family's release from the Marshalsea. They embark on a grand tour of Europe, attempting to adopt the airs and graces of high society, often with comedic and pathetic results. William, in particular, struggles to shed the "shame" of his past imprisonment and becomes increasingly pretentious.

Meanwhile, Arthur Clennam faces his own financial ruin due to a bad investment and eventually finds himself imprisoned in the Marshalsea. Amy, whose love for Arthur has grown throughout the novel, returns to London and comforts him in prison, mirroring the care she once gave her father.

The novel features a complex web of interconnected characters and subplots, including the mystery of a hidden legacy, the machinations of the sinister Rigaud (also known as Blandois), and the story of Arthur's true parentage. Ultimately, through perseverance, kindness, and the eventual unraveling of secrets, Amy and Arthur find happiness together, while the novel delivers a powerful critique of societal ills and the importance of compassion and humility.