Poor Charlie Bucket (Peter Ostrum) lives in poverty with his mother and four grandparents. On his way home from school one day, his paper route takes him past the gate of the town's mysterious, but highly-prized candy-maker, Willy Wonka (Gene Wilder). As Charlie peers through the gates, a man walks by, telling Charlie that 'nobody ever goes in, and nobody ever comes out.'
Later that night, Charlie discusses this with his Grandpa Joe (Jack Albertson). Joe explains that the man Charlie saw was right. Many years before, other candymakers were sending spies into his factory to steal Wonka's amazing candy secrets. Finally, Mr Wonka locked the gates, and banished all his workers from the factory. Shortly after this, the factory started up, but no one knows who is making Wonka's candies now.
The next day at school, word spreads quickly that a contest has been launched, with 5 golden tickets hidden in 5 ordinary Wonka bars. The big prize is that those who find these tickets, will get to visit Mr Wonka's long-isolated factory, and receive a lifetime supply of chocolate. The world then goes crazy, with Wonka candies being sold out at almost every store.
The first ticket is found by a gluttonous German boy, named Augustus Gloop (Michael Bollner).
The second ticket is found by a spoiled little girl named Veruca Salt (Julie Dawn Cole), whose father utilized his peanut factory workers to open Wonka bars from dawn until dusk.
The third ticket is found by a girl named Violet Beauregarde (Denise Nickerson), who is an avid gum chewer, having chewed a piece of gum for 3 months straight to achieve a world record.
The fourth ticket is found by a boy named Mike TeeVee (Paris Themmen), who is obsessed with television, particularly programs regarding cowboys.
For many years, a mysterious candy-maker, Mr. Willy Wonka (Gene Wilder), produced amazing treats from his factory in town. But the factory closed without notice a few years ago, then magically began making candy again. But without any employees or workers leaving or entering the factory.
Mr. Wonka decides to break his silence and launches a world-wide contest. Five golden tickets are hidden in his candy bars. The lucky finders will win an amazing tour of his candy making factory and a life-time supply of chocolate.
Four tickets are quickly won by various children around the world. Charlie finds a coin in the street and decides to buy two bars of candy. And of course, in the second bar is the last golden ticket.
He persuades his grandpa Joe (Jack Albertson) to climb out of bed for the first time in years and join him on the tour.
Charlie meets the other four children and parents and begins an amazing adventure through the magical chocolate factory.
One by one, the children become disqualified for displaying terrible qualities - gluttony, greed, stubborness and rudeness. Charlie breaks the rules too by stealing fizzie lifting drink. It makes him and Grandpa Joe float to the ceiling, which has to be washed and sterilized because of their improper activity.
Mr. Wonka erupts in a rage when Charlie asks for his prize of chocolate and orders him to leave the factory. Displaying humility and grace, Charlie gives back a sample of a prototype candy (Everlasting Gobstoppers), which becomes the key that opens the door to the factory. Because of that selfless act, Mr. Wonka reveals that Charlie has won the factory and must take over making candy. He invites his whole family to move into the facility and live happily ever after.