Fudge is desperate to appear to be doing something about the attacks on Muggle-borns at Hogwarts. Although he usually relies on Professor Dumbledore’s advice, Fudge ignores the Headmaster’s protests and sends Hagrid to Azkaban as a precautionary measure.
Cornelius Fudge, the Minister of Magic, is waiting for Harry at the entrance to the Leaky Cauldron as the Knight Bus arrives. A portly man dressed in a pin-striped cloak, Fudge leads Harry to a small parlour inside the pub, and explains that two members of the Accidental Magic Reversal Department were able to puncture the inflated Aunt Marge and modify her memory. Fudge tells Harry that whilst Harry's aunt and uncle are still angry, they will allow him back to Privet Drive in the summer. To Harry's astonishment, Fudge dismisses the idea of him being punished for blowing up his aunt, and organises for Harry to stay in the Leaky Cauldron for the remainder of the holidays on the condition that he does not to wander off into Muggle London. To Harry's disappointment, Fudge refuses to sign his Hogsmeade permission form in place of Harry's parent or guardian.
Fudge enters the Three Broomsticks deep in conversation with Hagrid. When questioned by Madam Rosmerta, he admits he is in Hogsmeade to help deal with the Sirius Black issue. He believes Black is still in the area, and defends the presence of the Dementors because of this. He explains to Rosmerta that Black was responsible for the deaths of Lily and James Potter. According to Fudge, Sirius had been secretly passing information to Voldemort, but was ready to publicly declare his loyalty. Barely a week after the Fidelius Charm had been performed, Black betrayed the Potters to Voldemort. When Voldemort fell, Black went on the run. He was found by Peter Pettigrew, who confronted him; Black blew Pettigrew to pieces in front of a crowd of Muggle witnesses. Fudge believes that although Voldemort's defeat unhinged Black for a while, he is not actually mad. Fudge was unnerved by how normal Black seemed when he visited him in Azkaban. Fudge is evasive about whether Black's plan is to rejoin Voldemort, but is horrified by the prospect.
Fudge stands talking to Professor Snape in the corridor outside the hospital wing, listening keenly to Snape's account of what happened in the Shrieking Shack. He tells Snape that he should be awarded the Order of Merlin, Second Class for his assistance in capturing Sirius, maybe even First Class, if Fudge can manage it.
Fudge doesn't take Harry's claims of Sirius Black's innocence seriously, and believes he is still confused from his ordeal. He is startled by Snape's attitude towards Harry and Hermione, and doesn't like when Snape shouts at Hermione. Fudge leaves the hospital wing to go and meet the Dementors. He tells Dumbledore that he will see him upstairs, and leaves the room with Snape.
After entering Hagrid's house, Fudge informs Hagrid that he needs to read him the official notice of execution. He tells Macnair that he must listen too, before proceeding to read the notice aloud. Fudge discovers Buckbeak's escape with the rest of the Committee. He makes his way back to the castle with the other men just after Harry, Hermione and Crookshanks enter the tunnel at the base of the Whomping Willow.
When Fudge discovers that Sirius Black has escaped he is apprehensive about what the Daily Prophet is going to publish about the botched capture. He is worried about them finding out about Buckbeak's escape too, as it will make the Ministry of Magic a laughing stock. He tells Dumbledore that the Dementors will be removed from the school, and is shocked that they tried to perform the Dementors' Kiss on a schoolboy. He leaves the hospital wing with Dumbledore, preparing to notify the Ministry of what has happened
Fudge is convinced by Dumbledore that Professor Lupin was trying to save Harry, Ron and Hermione, and is satisfied that Lupin hadn't been helping Sirius into the castle.
Fudge arrives in the Top Box at the Quidditch World Cup after the Weasleys, Harry and Hermione. He greets Harry like an old friend, shaking his hand in a fatherly fashion and asking how he is. He introduces Harry to the Bulgarian Minister for Magic, talking loudly as he tries to make the Minister understand him, even though it appears that the Bulgarian Minister doesn't speak English. He tells Harry that he struggles with languages, and is having difficulty communicating with the Bulgarian wizard. Fudge greets the Malfoy family when they arrive in the Top Box, and appears unaware of the animosity between Arthur and Lucius.
Fudge is outraged when he realises after the match that the Bulgarian Minister for Magic speaks English, and is irritated that the Minister has been letting him mime everything all day. Fudge, still looking disgruntled, is handed the Quidditch World Cup when it is brought into the Top Box; he shakes hands with all the Bulgarian Quidditch players, then presents the Cup to the Irish Quidditch team.
Fudge is standing beside Dumbledore's desk when Harry enters the Headmaster's office. He greets Harry jovially, and asks how he is. He tells Harry that he, Dumbledore and Professor Moody were discussing the night Mr Crouch appeared in the Forbidden Forest. He looks embarrassed when it becomes clear that Harry heard his theory that Madame Maxime was involved in Crouch's disappearance; Harry discredits it by saying he didn't see her. Fudge leaves the office with Moody and Dumbledore to make a short examination of the castle grounds.
Fudge steps in as the fifth judge for the third task in Mr Crouch's absence. He joins the teachers' table for the evening feast on the day of the third task. He looks stern and doesn't speak, sitting next to a red-eyed Madame Maxime. Fudge attends the third task along with the Hogwarts, Durmstrang and Beauxbatons students and teachers.
Fudge is horrified when he sees the two boys as they arrive back at Hogwarts, and quickly realises that Cedric Diggory is dead. He insists that Cedric is only injured to stop the crowd panicking and asks Dumbledore to speak to Cedric's parents before they see their son's body.
Fudge enters the hospital wing followed by Professors McGonagall and Snape. He demands to know where Dumbledore is, and is answered moments later when the Headmaster enters the room. Snape reveals that Fudge brought a Dementor with him to the castle, and allowed it to perform the Dementors' Kiss on Barty Crouch Junior. Fudge defends his decision to Dumbledore, and doesn't understand the need to keep a man he considers a raging lunatic to testify about his actions. Fudge is stunned when Dumbledore confirms that Crouch Junior was working under the instructions of Lord Voldemort, and thinks it preposterous to suggest that Voldemort has returned. He believes that Crouch Junior was a lunatic, and finds Harry's evidence very suspect. Fudge has read Rita Skeeter's articles in the Daily Prophet: the discovery that Harry is a Parseltongue, and the knowledge of the pains Harry experiences through his scar, make Fudge doubt his story. He is surprised that Dumbledore supports Harry's story, and begins to believe that those in the room are determined to start a panic that will destabilise the work of the thirteen years following the First Wizarding War. Fudge is further panicked when Dumbledore suggests removing the Dementors from Azkaban, and is outraged at the suggestion that they would betray the Ministry of Magic. He finds all of Dumbledore's suggestions worrying, and is horrified at the thought of what those actions would do to his career. Fudge bristles when Dumbledore states that he will act as he sees fit, and takes the statement to mean that Dumbledore will work against him, unable to believe that Voldemort has truly returned. When Professor Snape reveals the Dark Mark branded on his forearm to help corroborate Dumbledore's theories, Fudge doesn't appear to take in a word he says. He stares at the Mark, apparently disgusted, and tells Dumbledore that he has heard enough, and that he will be in touch about the running of the school. He pauses before leaving the hospital wing, striding over to Harry's bed and depositing a large bag of gold onto the bedside table: Harry's Triwizard winnings. He crams his bowler hat onto his head and walks out of the hospital wing, slamming the door behind him.
Fudge is standing by the fire in Dumbledore's office when Umbridge arrives with Harry in tow. He glares at Harry with a kind of vicious satisfaction, seemingly pleased that Harry has been caught doing something wrong. Fudge is incredulous when Harry denies knowing why he has been brought there, and tells Harry that an illegal student organisation has been discovered within Hogwarts. He asks Professor Umbridge to fetch the informant, Marietta Edgecombe.
Fudge greets Marietta when she arrives, and ask her to tell them what she knows. He leaps back in shock when he sees the word 'SNEAK' written in purple pustules across Marietta's face, almost landing himself in the fire. Fudge tries to persuade Marietta to talk about the illegal student meeting, but is unsuccessful. Fudge is rendered silent when Dumbledore reminds them that the ban on student societies was not put into effect until two days after the meeting in the Hog's Head. He attempts to regain control of the meeting after Marietta denies there were any further meetings other than the one that night, and is delighted when Umbridge produces a list taken from the Room of Requirement of the students who participated.
Fudge is confused when Dumbledore himself offers a confession; a look of understanding blazes across his face as he concludes that Dumbledore has been plotting against him. Radiant with glee, Fudge tells Percy to duplicate his notes on the meeting and send a copy to the Daily Prophet, and tells Dumbledore that he will be escorted back to the Ministry and formally charged. He is confused when Dumbledore says that he has no intention of being sent to Azkaban, and orders Dawlish and Shacklebolt to seize the Headmaster. Fudge is rendered unconscious during the scuffle between Dumbledore and the Ministry officials; when he wakes, Fudge is angry to discover that Dumbledore has escaped, and tells Professor McGonagall to escort Harry and Marietta to their dormitories.