The story follows the life of David Copperfield from childhood to maturity. David was born in Blunderstone, Suffolk, England, six months after the death of his father. David spends his early years in relative happiness with his loving, childish mother and their kindly housekeeper, Clara Peggotty. They call him Davy. When he is seven years old his mother marries Edward Murdstone. To get him out of the way, David is sent to lodge with Peggotty's family in Yarmouth. Her brother, fisherman Mr Peggotty, lives in a house built in an upturned boat on the beach, with his adopted relatives Emily and Ham, and an elderly widow, Mrs Gummidge. "Little Em'ly" is somewhat spoiled by her fond foster father, and David is in love with her. They call him Master Copperfield.
On his return, David is given good reason to dislike his stepfather, who believes exclusively in firmness, and has similar feelings for Murdstone's sister Jane, who moves into the house soon afterwards. Between them they tyrannize his poor mother, making her and David's lives miserable, and when, in consequence, David falls behind in his studies, Murdstone attempts to thrash him - partly to further pain his mother. David bites him and soon afterwards is sent away to Salem House, a boarding school, under a ruthless headmaster named Mr Creakle. There he befriends an older boy, James Steerforth, and Tommy Traddles. He develops an impassioned admiration for Steerforth, perceiving him as someone noble, who could do great things if he would, and one who pays attention to him.
David goes home for the holidays to learn that his mother has given birth to a baby boy. Shortly after David returns to Salem House, his mother and her baby die, and David returns home immediately. Peggotty marries the local carrier, Mr Barkis. Murdstone sends David to work for a wine merchant in London - a business of which Murdstone is a joint owner. David's landlord, Wilkins Micawber, is arrested for debt and sent to the King's Bench Prison, where he remains for several months, before being released and moving to Plymouth. No one remains to care for David in London, so he decides to run away, with Micawber advising him to head to Dover, to find his only known remaining relative, his eccentric and kind-hearted great-aunt Betsey Trotwood. She had come to Blunderstone at his birth, only to depart in ire upon learning that he was not a girl. However, she takes pity on him and agrees to raise him, despite Murdstone's attempt to regain custody of David, on condition that he always try to 'be as like his sister, Betsey Trotwood' as he can be, meaning that he is to endeavour to emulate the prospective namesake she was disappointed not to have. David's great-aunt renames him "Trotwood Copperfield" and addresses him as "Trot", one of several names David is called by in the novel.
David's aunt sends him to a better school than the last he attended. It is run by Dr Strong, whose methods inculcate honour and self-reliance in his pupils. During term, David lodges with the lawyer Mr Wickfield, and his daughter Agnes, who becomes David's friend and confidante. Wickfield's clerk, Uriah Heep, also lives at the house.
By devious means, Uriah Heep gradually gains a complete ascendancy over the aging and alcoholic Wickfield, to Agnes's great sorrow. Heep hopes, and maliciously confides to David, that he aspires to marry Agnes. Ultimately with the aid of Micawber, who has been employed by Heep as a secretary, his fraudulent behaviour is revealed. At the end of the book, David encounters him in prison, convicted of attempting to defraud the Bank of England.