The novel features both fictional and historical characters.
Johnny Tremain -The story's protagonist. Born Jonathan Lyte Tremain, he is a likeable but sometimes arrogant young teenager, a talented apprentice silversmith indentured at the age of 12 to Ephraim Lapham for seven years. Because his right hand is badly injured by molten silver, he is forced to seek another trade. Mrs. Lapham decides that, despite Ephraim's promise to never turn him out, he can no longer live with them because he is a drain on their meager resources and his hand renders him useless to support the family. Johnny was born in a convent in France. He returned with his mother Lavinia "Vinny" Lyte Tremain to Townsend, Maine, when she was certain she would no longer be recognized as a Lyte.
Rab Silsbee - Johnny's first true friend and role model. He is two years older than Johnny but taller, more mature, resourceful, brave, and admired, especially by Johnny. He introduces Johnny to the politics of Boston, where he is a member of the Sons of Liberty. He treats Cilla kindly, but mostly to tease Johnny. Rab is a Silsbee, known for their dignified aloof reserve, but a fervent, well-spoken Patriot. Rob drills with the Minute Men of Lexington using an old fowling piece, but yearns for a modern musket. He takes part in the Battle of Lexington where he is mortally wounded.
Priscilla Lapham - "Cilla" is slightly younger than Johnny. Unlike her older sisters, Cilla is petite and a blossoming beauty. Over time, Cilla and Johnny develop genuine love for each other. Cilla is intended to wed Mr. Tweedie after her older sisters both refuse, but she too balks and goes to work for the Lytes. She is Mrs. Lapham's third daughter.
Isannah Lapham - "Izzy." The youngest daughter of Mrs. Lapham, Isannah is a beautiful but frail child who needs close caring for at all times. Once-sweet Isannah is beloved by her older sister, Cilla but eventually becomes selfish and vain. Isannah's golden-haired, brown-eyed, beauty attracts a great deal of attention, most significantly from Lavinia Lyte. Lavinia takes Isannah as her protege and introduces her to high society, separating her from her family and their working-class way of life.
Ephraim Lapham - A Boston silversmith, and Johnny's master at the beginning of the novel. Mr. Lapham is pious and kind, but old, frail, and no longer the master smith of his youth and unfortunately dies soon after Johnny leaves his apprenticeship.
Mr. Tweedie - A 40-year-old from Baltimore, Maryland who becomes Mr. Lapham's business partner after Johnny's accident. Tweedie is a "queer" man, unliked by many. Johnny calls him a "Squeak-Pig".
Mrs. Lapham - later Mrs. Tweedie - Ephraim Lapham's widowed daughter-in-law. Mrs. Lapham is a dedicated, hardworking mother and a no-nonsense taskmaster to the apprentices. She works as the housekeeper in Mr. Lapham's house and shop. When none of her daughters will do so, she marries Mr. Tweedie to keep the silversmith shop in the Lapham family.
Dorcas Lapham - Mrs. Lapham's second daughter. Although the stocky Dorcas longs to be elegant and sophisticated, she falls in love with the poverty-stricken Frizel, Jr., and elopes to avoid marrying Mr. Tweedie.
Madge Lapham - Mrs. Lapham's oldest daughter. Like Mrs. Lapham, Madge is tough and capable. She falls in love and elopes with Sergeant Gale, a British soldier. Madge, like Dorcas, was engaged to marry Mr. Tweedie and eloped with Sergeant Gale to avoid marrying him.
Dove - An apprentice in the Lapham shop and rival of Johnny whose first name had been forgotten. He is older than Johnny, stupid and given to malicious behavior, and has been an apprentice two years longer but still can only perform menial duties. Dove both resents and looks up to Johnny. He attempts to steal tea during the Boston Tea Party. After Mr. Lapham dies, Dove takes a job caring for British officers' horses during Boston's occupation. Johnny despises Dove and cannot bring himself to forgive him as Mr. Lapham counseled, but his thirst for revenge dies when Dove is persistently abused by his Redcoat masters.
Dusty Miller - Mr. Lapham's youngest apprentice. Before Johnny's accident, Dusty idolized him. After Johnny leaves the silversmith shop, Dusty runs away to sea.
Mr. Lorne - Rab's master and uncle by marriage. Mr. Lorne owns the print shop that publishes the Boston Observer, a seditious Whig (Patriot) newspaper.
Mrs. Jenifer Lorne - Mr. Lorne's wife and Rab's aunt. Mrs. Lorne sees through Johnny's arrogant exterior to treat him as a lonely boy. She becomes like a mother to him and is the actual mother of an infant son who is unmistakeably a Silsbee. Johnny nicknames him "Rabbit", as a word play on Rab's name.
Jonathan Lyte - A wealthy Boston merchant and Johnny's great-uncle. Crooked and cruel, Lyte tries to make a profit by making friends on both sides of the colonial struggle, the Loyalists and the Patriots, but as tensions mount in Boston, Lyte is exposed as a Tory (Loyalist). He becomes gravely ill after his country home in Milton is attacked by a Patriot mob. On the eve of war, Lyte and his family depart for London.
Lavinia Lyte - Jonathan Lyte's beautiful daughter, just returned from living in London. Lavinia is the most desirable socialite in Boston. Enchanted by Isannah's ethereal beauty, Lavinia Lyte takes the child away from her family to live amidst the wealth of the Lyte household as a sort of pet. She is also Johnny's cousin, which she reveals at the end of the book. Johnny has a romantic infatuation for her, but he pretends to strongly dislike her to hide this.
Mrs. Bessie - The Lytes' cook and Cilla's only friend in the Lyte household. Mrs. Bessie is an ardent Whig and a confidante of Samuel Adams, but she nonetheless remains loyal to her Tory employers. When the Lytes leave Boston, Bessie and Cilla are left behind to look after their house. Johnny admires Mrs. Bessie.
Lavinia (Vinny) Lyte Tremain - Johnny's mother. She dies before the novel begins. She was born Lavinia Lyte, a name favored for Lyte females, and was a beautiful but impetuously wild young woman. The family turned her out for eloping with Charles Tremain.
Charles Tremain - Johnny's father. Charles Tremain was a French naval surgeon taken as a British prisoner of war during the French and Indian War. While he was held as a prisoner in Boston, using the name Dr. Latour out of shame at being a prisoner, he met and courted Johnny's mother. They eloped and were married aboard a ship traveling to Marseilles, France, where Charles died of cholera and Johnny was born three months later.
Lydia - The African washerwoman at the Afric Queen, a tavern where many British officers are quartered. Lydia is a rebel sympathizer who, because of her connection to the British soldiers, gathers information for the rebel forces. She is described as handsome by Johnny.
Sewall - A poor relative of the Lytes who works as a clerk in Jonathan Lyte's office. Sewall is kind and brave; he runs off to join the Minute Men and becomes the owner of the Afric Queen after the war.
Pumpkin - A British private soldier stationed in Boston. Pumpkin is a secret Whig whose dream is to own a piece of land and homestead a farm. Because he is poor, he can only achieve his dream in America. Johnny helps him desert from the army in exchange for his musket, to give to Rab, but Pumpkin is captured and executed by a firing squad.
Sergeant Gale - A British non-commissioned Officer who marries Madge Lapham, Mrs. Lapham's eldest daughter. He is noted to be short but tough.
Lieutenant Stranger - A friendly but often haughty British officer stationed in Boston. He develops a mild friendship with Johnny. He is young, eager to fight, and reminds Johnny a lot of Rab.
Samuel Adams - Political leader of the Revolutionary forces. He wrote numerous pamphlets inciting and inspiring the revolution.
John Hancock - One of the wealthiest men in Boston and a leader of the Whigs. Johnny disfigures his hand while making a silver basin for him.
Doctor Joseph Warren - One of the leaders of the Whigs in Boston. In the novel's climax, he is shown preparing to operate on scar tissue in Johnny's disfigured hand. Foreshadowing indicates that the operation will be a success, allowing Johnny to enlist in the rebel army.
Paul Revere - The best silversmith in Boston and an important Whig, known to American history for his midnight ride to caution the Minutemen of approaching British soldiers.
James Otis, Jr. - A lawyer and architect of the ideals of the American Revolution; his career was shortened by bouts of insanity caused after being beaten about the head by a British soldier. In the novel, Otis inspires the Whig leaders to fight for the rights of all people, not just Americans. He warns that some will give their lives, foreshadowing the death of Rab.
Governor Thomas Hutchinson - The governor of Massachusetts prior to the occupation by the British army.
Thomas Gage - British General and military governor of Boston during the occupation.
John Pitcairn and Francis Smith - British commanding officers at the Battles of Lexington and Concord.
Josiah Quincy II- The young lawyer and member of the Sons of Liberty who defends Johnny in court when accused of theft by the Lytes.