Tom Sawyer doesn't like school much. Escaping from the schoolhouse, he's off to the woods to catch a wild pig with his friend Huck. Their attempts to sell the pig at the harbor end with a wild disturbance on the steamboat.

Tom is dismayed when Aunt Polly tells him he must spend his Saturday whitewashing the fence. Too long to paint in one day, Tom convinces his friends of the joys of the job, and soon has all the help he needs.

Tom goes to the harbor to meet his cousin Mary, and sees Becky Thacher for the first time. Her family moves into St. Petersburg, and Tom falls in love.

Tom tries to arouse Becky's interest at Sunday School, but is ignored. That night Old Sam shows him a special charm to make wishes come true.

Tom arrives at school late and finds that Becky is in his class. He finally manages to become friends with her, and promises to visit - forgetting another promise he has made to Huck.

Huck is offended that Tom forgot his promise. The next few days Tom works with Huck, telling Becky he is busy helping his sick aunt. Becky discovers his lie but her anger is replaced with surprise when she sees Huck's newly built tree house.

Tom just can't get along with his new classmate Alfred, and challenges him to a fighting match. On the way home, the boat they are aboard sinks and Tom rescues Alfred, who can't swim at all - winning Becky's praise.

A large steamship comes to St Petersburg. Tom and Huck steal aboard for a trip. Next day, Tom boasts about their adventure, fascinating his classmates.

Aunt Polly falls sick and is struck with an idea. She calls Tom to her bedside, pretending to be dying. Aunt Polly tells Tom she cannot go to heaven unless he promises to be a good boy but Tom refuses to promise, because he doesn't want his aunt to die.

The villagers do not like drunken Muff and Indian Joe. Tom and Huck rescue Muff and he, in return, tells them about a treasure buried near St Petersburg. The boys decide they will find the treasure, and Indian Joe joins Muff in his search.

Mr. Dobbins, the schoolteacher, doesn't trust Tom, but all Tom's classmates like him. Younger brother Sid saves Tom from punishment at school. Later, Tom and Huck decide to conduct their treasure hunt at night, to avoid Indian Joe.

Tom gives Becky an engagement kiss. But with a slip of the tongue, he tells her that he had once been engaged to Amy. Becky is furious, and Tom becomes so discouraged he ends his treasure hunt.

After Becky ignores Tom for five days, he decides to run away from home to be a pirate. During the night he sails to Jackson Island on a raft, along with Huck and Ben.

Tom, Huck and Ben enjoy their adventure on the island while everyone in the village worries about their disappearance. A rainstorm washes away their raft, and it is found by a villager broken to pieces.

The villagers believe the boys have drowned in the river. Though they play all day on the island, Ben misses his home. Tom returns secretly for news of the village and sees Aunt Polly praying for his safety.

Ben and Huck miss the village, so Tom proposes that they return on the very day of their funeral. No other village children, Tom decides, have ever become the center of so much attention.

After the funeral Tom is a hero at school, and everyone wants to hear his story. Charlie inks Tom's schoolbook out of jealousy, and Tom is punished. Becky saw what happened and feels guilty that she did not tell the truth.

Becky accidentally tears a page of Mr. Dobbins' precious book on medical science, and Tom takes the blame. Becky makes up with him.

Frog leaping matches are popular with the school students, and Tom trains his frog to be a great leaper. Charlie doesn't want to hand over his championship, so he stuffs Tom's frog with pebbles.

Tom and Huck discover that Mr. Dobbins wears a wig. On the last day of school, when the teacher whips every student, even girls, for sleeping during class, Tom hits on a capital idea for revenge.

Sid comes down with the mumps just as summer vacation starts. Tom doesn't want to get sick and spoil his holiday. Just then two men come to town with Water of Life, guaranteed to cure every disease.

Tom distributes handbills in return for the medicine. It sells like hotcakes, then the two men disappear. The medicine turns out to be a sham. Tom doesn't get the mumps, but he makes many trips to the outhouse.

Tom goes fishing with Huck and Becky. They catch a big one, but only after Becky jumps in to lend a hand.

Becky's great aunt has no children of her own, and decides to adopt Huck. Tom makes him take a bath, dresses him up, and takes him to Becky's house. Huck doesn't like anything that binds, including a tie, and declines the offer.

Alfred hones his swimming skills in order to show up Tom. At his birthday party he challenges Tom to a swimming race and wins. Tom then challenges Alfred to a contest to see who can stay under the water the longest.