Suddenly before us stands Willy Wonka, the world-renowned candy maker and chocolatier ("The Candy Man') - a genius who believes he is a forgotten man. Wonka transforms himself into the world-weary owner of a candy shop who makes the acquaintance of young Charlie Bucket, who idolizes Willy Wonka. When the shop owner tells Charlie that Wonka is about to make a comeback, the boy is thrilled but exasperated that the shop owner does not seem to know just who Willy Wonka is ("Willy Wonka! Willy Wonka!"). Charlie comes from a poor, fatherless family that scrounges for food, and he lives for his birthday each year when he receives as a gift a single Willy Wonka Chocolate Bar. Back home, Charlie decides to write a letter to Willy Wonka ("A Letter from Charlie Bucket"), in which he expresses his wonder and admiration (as well as some ideas) for the candy maker.

Charlie and the Bucket family read some exciting news in the paper: Willy Wonka has hidden five golden tickets inside his chocolate bars. Whoever finds one will win a tour of his chocolate factory, lead by Wonka himself. Mrs. Bucket tells Charlie they do not have enough money for him to buy a chocolate bar before his birthday. At the candy store, a discourage Charlie tells the shop owner (still Wonka in disguise) that he doesn't even want to think about chocolate. The news breaks that the first winner of a golden ticket is a food-loving German boy ("More of Him to Love"), adored by his mother and named Augustus Gloop. The second ("When Veruca Says") is Veruca Salt, the spoiled-rotten daughter of a Russian oligarch. The winner of the third ticket ("The Queen of Pop") is Violet Beauregarde, whose publicity hound of a father is turning her pursuit of a world record for chewing gum into a media event. The fourth ticket ("That Little Man of Mine") goes to Mike Teavee, a brat who is mesmerized by social media, to the delight of his mother.

On his birthday, Charlie receives his annual chocolate bar, but finds no ticket when he unwraps it. Outside the candy shop, he runs into the owner, who drops a dollar on the ground as he leaves. Charlie uses it to buy a Wonka bar from Mrs. Green's cart and discovers a golden ticket, making him the fifth winner. Charlie and his whole family celebrate the news ("I've Got a Golden Ticket" / "Grandpa Joe") that he is headed to Willy Wonka's Chocolate Factory, where Grandpa Joe will join him. At long last, Willy Wonka welcomes the winners into his factory, teasing them about what lies ahead for them ("It Must Be Believed to Be Seen").

Inside the factory, Wonka introduces the winners to the wonders they are about to encounter - and some things they need to remember ("Strike That, Reverse It"). Charlie and Grandpa Joe are in awe of Wonka and what the magical experience has to offer ("Pure Imagination"), while the other children are greedy and impatient. One by one, the ticket holders become victims of their own appetites. Augustus Gloop's insatiable hunger for the chocolate waterfall makes him the first victim ("The Oompa Loompa Song" / "Auf Wiedersehen Augustus Gloop"), his fate determined by the mysterious Oompa Loompas who do Wonka's bidding. His warnings fall on deaf ears. Violet is then the next golden ticket holder to vanish ("You Got Whatcha Want") followed by Veruca ("Veruca's Nutcracker Sweet"), and finally Mike Teavee ("Vidiots"). Ultimately, there is only Charlie, in whom Willy Wonka sees an heir to his magical mission. He welcomes Charlie into a magical glass elevator that takes them up, up, up, so the boy can see everything that will be his ("The View from Here") - a happy home and limitless future, thanks to the Candy Man.