"Little Dorrit" is Amy, born in debtor's prison, the youngest child of debtor William Dorrit, an inmate of the Marshalsea. The two are befriended by a man whose wife hires Little Dorrit as a seamstress. When William Dorrit inherits a fortune, he escapes the Marshalsea, and the newly wealthy family travels to Italy.

Meantime, their benefactor falls onto hard times of his own, when he becomes the victim of a gigantic fraud perpetrated by an eminent financier and is himself sentenced to the Marshalsea. Little Dorrit finds him there, and a relationship develops between them that juxtaposes ambition with humility, acquisitiveness with generosity, and regret despite good fortune held up against optimism within dire circumstance.

Some of Dickens' most memorable comic characters appear in Little Dorrit, among them Mrs. General, the highly correct governess-companion who advocates the words "Papa, potatoes, prunes and prism" as giving "a pretty form to the lips."