The Prince and the Pauper tells the tale of two boys who trade clothing one afternoon and, as a result, they trade lives as well. After many adventures, matters are set right again, with one of the boys resuming his rightful, royal position and the other boy accepting a position that recognizes his innate intelligence and good heartedness.
One of these boys is the long-awaited male heir to the throne of England, Edward Tudor, son of Henry VIII. The other boy is Tom Canty, the unloved son of a beggar and thief. Coincidentally, Tom Canty and Edward Tudor were born in London on the same day.
Tom Canty's life in Offal Court, off Pudding Lane, is a hard life in one of London's poorest neighborhoods. He is forced by his father to go out begging daily, and he is beaten severely if he returns empty-handed. Father Andrew, however, provides him some respite from this life by telling him tales about the nobility, while instructing him in morality, reading, writing, and Latin. Treasuring these tales, which tell of a considerably better life, Tom Canty imaginatively relives them in his daydreams.
One day, Tom's daydreaming leads him out of the city of London, past the palaces of the rich, and finally to Westminster, where he actually sees Edward Tudor at play on the other side of a fence. Simultaneously, the prince notices Tom when he sees a soldier roughly pulling the young boy away from the fence; the prince rebukes the soldier and invites Tom into the palace. Each of the boys is fascinated by the other's life — Tom, by the luxury and the cleanliness that Edward has, and Edward, by the freedom that Tom has. To get a "feeling" of the other's life, they exchange clothing and discover that they look very much alike.
When the prince discovers a bruise on Tom's hand, he rushes out of the palace, paying no heed to the way he is dressed, to rebuke the guard. The guard, believing that the prince is the pauper, immediately puts him out of the gates, and thus the stage is set for Edward Tudor to experience the life of a commoner and for Tom Canty to live the life of a real-life prince.
Imperiously and angrily proclaiming that he is the Prince of Wales, Edward is mocked by the crowd around the royal gate, beaten, and has several dogs set upon him; all the while asserting that he is the son of the king. Chased back into London, Edward wanders around, not knowing where to go until he is finally collared by John Canty, Tom's father, and dragged off to Offal Court.
In the meantime, young Tom Canty has been left in the prince's royal apartment in the palace. At first, he enjoys the luxury of his surroundings, but he becomes increasingly apprehensive about what will happen to him if he is discovered in the prince's clothing. The Lady Jane Grey talks with him and becomes very confused about Tom's behavior; word quickly spreads that the prince is mad. Every time that Tom tries to say something to dispel this idea, it makes those around him only more convinced that the prince has indeed gone mad.
After talking with his "son," Henry VIII gives orders: first, he commands that the Duke of Norfolk be killed so that the prince can be immediately named heir apparent with no opposition. Second, he orders that all persons in the court say nothing about the prince's madness and that they ignore any indications of it. Finally, he orders his "son" to say no more about living in Offal Court and to try to regain his mental health. To this end, the Lord St. John and the Lord Hertford are to be his companions, to watch over him, and to remind him of what he is to do.
The first ceremony that Tom must undergo is dinner. Although he blunders frequently, his behavior is overlooked. Afterward, he finds a book dealing with the etiquette of the English court, and he begins the process of learning to cope in his new position. His next ordeal is a city dinner in London, toward which he and his entourage move in great splendor along the Thames River.
The scene then shifts momentarily to the Prince of Wales, who is now in the clutches of John Canty. He is brought to the filthy room where the Cantys live and is put on display to show the neighborhood his mad delusion that he is the Prince of Wales; later, he is beaten because he brought no money home.
Late that night, the Cantys are awakened by someone who has come to tell them that the man whom John Canty struck with his cudgel, while bringing his "son" home, has died. They all leave immediately, Canty keeping the prince in tow. The prince, however, manages to slip away from old Canty.
While Tom dines with the nobility and watches the pageantry of the dinner, the real prince stands outside the Guildhall, trying to get in, asserting that he is the true Prince of Wales. The mob jeers at him and would have thoroughly beaten him if Miles Hendon had not suddenly appeared and protected him. While the prince and Hendon are struggling with the crowd outside, and while the nobility is having a merry time inside the Guildhall, a messenger brings the news that Henry VIII is dead. Tom Canty is thus suddenly elevated from prince to king, and his first act is to free the Duke of Norfolk.
Hendon, meanwhile, leads the prince through the crowd toward his lodgings in an inn on London Bridge, then a city unto itself. John Canty, however, intercepts them and tries to take the prince, whom he still believes to be his son, but Hendon sends him away. In Hendon's rooms, the prince acts out his accustomed role and expects Hendon to serve him; Hendon does so, without a protest. As a reward for his help and kindness, Hendon is granted the right to sit in the presence of the king and is made a knight.
In the morning, Hendon leaves while the prince is still sleeping and goes out to buy new clothes for the boy. When he returns, however, the prince is gone, lured away by a boy who is later joined by a ruffian as they head toward Southwark. Although Hendon tries to follow, he loses the trail.
That same morning, Tom Canty is awakened, dressed, and fed; then the Lord Hertford takes him into the throne room, where he must sit through many tedious reports on affairs of state. Although Tom is learning to handle such situations, the Lord Hertford prevents him from making several blunders. In the afternoon, Tom makes good use of an interview with Humphrey Marlow, his "whipping-boy," to learn many of the things he needs to know; from this point on, Tom uses every opportunity to learn, and to remember, important royal matters.
The next two days are similar to the first, and Tom becomes more accustomed to what he must do. On the fourth day, however, the noise of a mob diverts Tom's attention. Looking out the window, he asks what the cause of this is and, after hearing about the trouble, he has the three condemned people brought before him. Questioning them shrewdly and disposing of their sentences decisively, he gains the admiration of all those present; his court also begins to wonder about the so-called rumors of his madness. With the new confidence that his actions have given him, Tom eats the state dinner, before all those who care to watch, without qualm, and without error.
The prince, in the meantime, is lured into an old country barn by John Canty and Hugo, his accomplice. He falls asleep on a pile of straw, and when he awakens, he hears many tales of injustice at the hands of the law. Outraged, he declares such laws should be abolished. This, as well as his assertion that he is the King of England, earns him the mockery of the troop of vagabonds who have joined Canty and Hugo. Forced to travel with these vagabonds, the prince nevertheless refuses to take part in their escapades, and he finally manages to escape from Hugo's custody when he tells a man that Hugo is a thief. He then wanders alone across the countryside, driven away whenever he begs for food or rest, until at last he finds an empty barn. Sleeping that night next to a calf, the prince is awakened by two young children who believe his story about his royal claim and take him to their mother. The woman feeds him and sets him to doing a variety of household tasks. As he is working, however, he sees Canty and Hugo arriving in front of the house, so he runs off toward the woods. There, he makes his way until he reaches a hermit's hut. The hermit, who is genuinely mad, feeds the boy and cares for him, but when he hears that the boy is the King of England, son of Henry VIII, he becomes consumed with revenge; he ties up the prince and is about to plunge a knife into him when Miles Hendon arrives at the door. The hermit manages to lead Hendon away, but, inadvertently, his absence allows John Canty and Hugo to take the prince with them.
Once again, Hugo tries to make the Prince Participate in begging and thieving; the prince however, steadfastly refuses to have anything to do with such activities. Hugo therefore decides to put the prince into the hands of the law, which he accomplishes by snatching a bundle, thrusting it into the prince's arms, and dashing away. The appearance of guilt is enough for the crowd that gathers, and the burliest of them is about to beat the prince when Miles Hendon once again appears. To appease the crowd, Miles and the prince must go before the magistrate. The judge is kindly, and the sentence is short. Hendon then manages to convince the sheriff that the wisest course would be to free the boy, and the two leave, headed toward Hendon Hall, from which Miles has been absent for some ten years.
When they arrive there, Miles's brother Hugh and the Lady Edith, who once loved Miles, deny that Miles is still alive. In fact, Hugh Hendon has Miles arrested as an impostor, and the prince is taken to jail along with him. There, the prince discovers the filthy conditions of his country's prisons, and he hears more stories about the many injustices of English laws. Finally, Miles is sentenced to sit two hours in the pillory; he also takes twelve lashes because the prince once again tries to assert himself. When the two are released at last, they turn back toward London.
Coincidentally, as the prince is returning to London, Tom Canty is rapidly learning to be a king and is preparing for his coronation. On Coronation Day, he rides in a grand procession through London. Riding past Offal Court, he sees his mother, and he denies knowing her; immediately, however, he is stricken with remorse.
The ceremony begins; then, suddenly, just as the Archbishop of Canterbury is about to place the crown on Tom's head, the real prince steps forward and forbids it. Tom affirms the boy's claim. Several inconclusive tests are tried in order to determine the identity of the boys, and finally the location of the Great Seal of England is suggested. With some prompting from Tom, Edward Tudor tells the Lord St. John where the seal is to be found, thus establishing his true right to the throne of England.
When Miles Hendon, who has been separated from the prince, appears outside Westminster, he is arrested and brought before the newly crowned king. Having believed throughout their travels together that the boy was mad, Hendon cannot believe that his young friend, now on the throne, is the same person. To test him, he pulls up a chair and sits in his presence; Edward affirms Miles's right to do so, and he also affirms that he has made Hendon a knight and that, furthermore, Hendon is now a peer of England, Earl of Kent. Later, Tom Canty is made the "King's Ward," and his sisters and his mother are granted lifetime care at Christ's Hospital.
The last chapter ties up loose ends of the plot: Hugh Hendon, though not prosecuted, leaves England and goes to the Continent; the Lady Edith marries Miles; Edward amply rewards those who were land to him, punishes those who were not, and makes reparations to those who suffered from the cruel injustice of English laws. Throughout his short life and reign, Edward Tudor always remembers his adventures and reigns more mercifully because of them.