A Newberry Award-winning children's novel, The Witch of Blackbird Pond follows the story of 16-year-old Kit Tyler as her family immigrates from Barbados to Connecticut in the late 1600s. Her unusual customs, such as the ability to swim, and her refusal to conform make her an outcast among most in the strict Puritan society of her new home, with many accusing her of being a witch, but a few true friends allow Kit to find happiness at last as they help her prove her innocence.
In April 1687, 16-year-old Katherine Tyler (known throughout the story as Kit Tyler) leaves her home in Barbados after her grandfather dies and a 50-year-old man tries to marry her. She goes to Wethersfield, Connecticut to live with her Aunt Rachel and Uncle Matthew in their Puritan community.
In Connecticut, there is a brief stop in Saybrook, a small town just downriver from Wethersfield, where four new passengers board the Dolphin , the ship on which Kit is traveling. As the small rowboat returns to the ship, a small girl named Prudence accidentally drops her doll in the water and begs her mother to get it back for her. Her mother, Goodwife Cruff, harshly strikes Prudence and tells her not to be foolish. Impulsively, Kit jumps into the water and retrieves the doll. She nearly freezes in the frigid water because she was used to the pleasantly warm water in Barbados, her old home. When she returns to the rowboat, she is met with astonished suspicion, as few people in Connecticut could swim so well.
Goodwife Cruff is the most cynical of them all, believing Kit is a witch, saying, "No respectable woman could stay afloat like that." But Kit knew how to swim because she lived in the islands. On the slow trip upriver, Kit befriends John Holbrook, another passenger coming to Wethersfield to study with Reverend Gershom Bulkeley. After the Dolphin reaches Wethersfield, Kit admits to the captain of the ship that neither her aunt nor uncle knows she is coming. She says that they would welcome her because she is family.
When she arrives in Wethersfield, Kit finds Wethersfield very different from Barbados. In her previous home, she had servants, but here she is expected to work along with the rest of the family. There is none of the luxury to which she was accustomed, and even the weather is miserably cold. She has two cousins, Mercy (who is crippled) and Judith. She is required to attend church meeting services twice each Sunday, which she finds long and dull. She meets the rich, 19-year-old William Ashby, who begins courting her, though she does not care for him; originally, her cousin Judith had hoped to marry William, but soon sets her sights on John Holbrook, now a divinity student studying with local minister Gershom Bulkeley.
Kit's life improves when she and Mercy begin teaching the dame school for the young children of Wethersfield who are preparing for traditional school. Everything goes well until one day, bored with the normal lessons, Kit decides the children will act out a part from the Bible, the tale of the Good Samaritan. Mr. Eleazer Kimberly, the head of the school, enters the house just as things get out of hand. He is outraged at Kit for having the audacity to act out something from the Bible and shuts down the school. Heartbroken, Kit flees to the meadows where she meets and befriends the kind, elderly Hannah Tupper, who was outlawed from the Massachusetts colony because she is a Quaker, and does not attend Meeting. As fellow outcasts, Kit and Hannah develop a deep bond, and even after her uncle forbids Kit to continue the friendship, Kit keeps visiting Hannah.
During one of her visits, she again meets the handsome Nathaniel (Nat) Eaton, son of the captain of the Dolphin . Without realizing it, she falls in love with him, and though he doesn't say so, Nat loves her as well. Unfortunately, Nat is banished from Wethersfield after setting lit jack-o-lanterns in the windows of William Ashby's unfinished home with two of his shipmates out of jealousy; he will get 30 lashes if he returns to Wethersfield. Kit also begins secretly teaching Prudence to read and write; Goodwife Cruff claims the child is a halfwit and refuses to allow her to attend the dame school.
When a deadly illness sweeps through Wethersfield, a mob gathers to kill Hannah by burning her house, since everyone believes she is a witch who has cursed the town. Kit risks her life to warn Hannah, and the two women escape to the river just as the Dolphin appears from the early morning mist. Kit flags it down, and she explains to Nat the events of the night. Hannah refuses to leave without her cat, so Nat courageously dashes ashore, risking trouble with the town council for stepping foot in Wethersfield. After taking Hannah aboard, Nat then invites Kit to come with them. She refuses, explaining how Mercy is gravely ill, though Nat believes Kit fears risking her engagement to William Ashby.
After the Dolphin sails away, Kit returns home to find that Mercy's fever has broken. In the middle of the same night, the townspeople come for Kit; Goodwife Cruff's husband has accused Kit of being a witch. The next day, after a night in the sheriff's freezing shed, she is asked to explain the presence of her hornbook in Hannah's house and a copybook with Prudence's name written throughout, as the townspeople fear that she and Hannah had been casting a spell over the girl. Kit refuses to explain that it is Prudence herself who wrote her name in the book, as she does not wish Prudence to get in trouble with her parents. Then, just as the case seems to be decided, Nat appears with Prudence, who testifies that she herself wrote her name in the hornbook.
To demonstrate her literacy, Prudence reads a Bible passage and writes her name, thus convincing her father both that she is intelligent and that no witchcraft could be involved, as the devil would be foolish to allow a child to be taught to use the Bible against himself. While Nat is initially in trouble for returning and evades capture, Matthew Wood intervenes on his behalf and gets the sentence remitted because Nat came back to see justice done, not to cause further mayhem.
Soon after, two engagements are announced: Judith to William Ashby and Mercy to John Holbrook. Kit decides to return to Barbados. However, she soon realizes that she is truly in love with Nat, and she waits for him to return. Nat returns to Wethersfield with his own ship, the Witch , named for Kit. Kit asks to come on board the Witch but Nat says no, not till he can marry Kit. The two then head off to ask Uncle Matthew for permission.