Note that mistakes could differ between the US and UK editions, and that many mistakes were corrected in later editions, thus they may not exist in your own copy.
Harry Potter and the Philosopher‘s/Sorcerer‘s Stone
- It mentions that the snake in the zoo winked at Harry. Harry can't be blamed for being so surprised, as snakes don't have movable eyelids.
- When Hagrid comes and gets Harry out of the little hut on the rock, they use the boat that the Dursleys used earlier to get to the rock. So how do the Dursleys get off the rock?
- On Harry's equipment list in the letter from Hogwarts, "1 wand" is listed twice. This was corrected quickly and only appears in the earlier versions.
- Harry's letter from Hogwarts says he may bring a cat, an owl, or a toad, but Ron brings his rat, Scabbers.
- Arguable: When Hagrid brought Harry to Diagon Alley for the first time, Harry heard a woman say "Seventeen sickles an ounce for Dragon Liver. They're mad." But Hagrid told Harry that there were seventeen sickles in a galleon, so that would be like saying "100 pennies" instead of a dollar. Think of it this way: If the Dragon Liver weighed three pounds, a galleon (or for our purposes, a dollar) per ounce is quite a lot of money.
- Harry buys the book One Thousand Magical Herbs and Fungi, but later in the book it says that Harry looked up "dittany" in One Hundred Magical
Herbs and Fungi.
- When Harry looked up at the Sorting Hat's stool, there were only three people left to be sorted. Professor McGonagall calls the names of four more people instead.
- In the chapter "The Sorting Hat," Nearly Headless Nick says that he hasn't eaten in "nearly four hundred years;" but in the second book, Harry goes to Nick's 500th Deathday Party, meaning that Nearly Headless Nick has been dead for 500 years, not 400
- It says that Hermione lent Harry Quidditch Through the Ages: "She had also lent him Quidditch Through the Ages, which turned out to be a very interesting read." On page 46, paragraph three of QTTA, it says: "The most successful Japanese team, The Toyohashi Tengu, narrowly missed a win over Lithuania's Gorodok gargoyles in 1994." However, Harry borrows QTTA in Book 1, which is set in 1991.
- Fred says: "We haven't won [the Quidditch Cup] since Charlie left..." However, according to JKR, Charlie is three years older than Percy (who is in his fifth year at the time), so Charlie should still have been in Hogwarts the year before. This makes Fred's statement as: "We haven't won since last year!"
- "Wednesday night found Hermione and Harry sitting alone in the common room... The clock on the wall had just chimed midnight when the portrait hole burst open. Ron appeared..." But soon after, it says: "They had to study the night skies through their telescopes every Wednesday at midnight..." So are they cutting class to discuss Norbert?
- The trio, who are coming from Gryffindor Tower, go up two flights of stairs to get to the third floor. Gryffindor Tower is on the seventh floor, so they should have gone down, not up.
- At the beginning of the chess match, Ron is the knight in the giant chess set. However, it later says that he had to "move ahead one" so that the queen could take him, opening the path for Harry to checkmate the king. If he was a knight, he could only move 1) ahead one, sideways two, or 2) ahead two, sideways one, like an "L."
- Dumbledore said that he and Hermione's owl crossed in mid-air. However, later Hermione said that they ran into Dumbledore on the way to the Owlery to send him the owl.
- Ron says: "Well Harry, you take the place of that bishop, and Hermione, you go next to him instead of that castle." But the castle is next to the knight, not the bishop.
Harry Potter and the Chamber of Secrets
- The day of Harry's birthday, Rowling says, "And then, exactly a year ago, Hogwarts had written to Harry..." but they had actually written before Harry's eleventh birthday. He'd been receiving them before, but he just never had the chance to read one. So technically he had been written to before his eleventh birthday.
- It states that Nearly Headless Nick "took several deep breaths, and then said, in a far calmer tone, 'So what's bothering you?'" However, in GoF, Myrtle says that ghosts do not breathe: "When I can't ...when I haven't...not for ages..."
- "Several (freshly caught Cornish pixies) shot through the window, showering the back row with broken glass." The glass would have splintered outward, not back into the classroom.
- It states, "...Harry was dragging his feet along the second-floor corridor to Lockhart's office. He gritted his teeth and knocked." However, after Mrs. Norris is found petrified on the second floor, Lockhart urges Professor Dumbledore to use his office to examine her, saying that it is just upstairs. That would mean that his office is on the third floor, not the second.
- (Note: This mistake applies only to the US edition.) When Professor McGonagall took Harry to Professor Dumbledore's office, the password was "Lemon drop." But then in the fourth book when he's going to tell Dumbledore about Mr. Crouch in the forest, it says: "...five minutes later he was hurtling towards a stone gargoyle standing halfway along an empty corridor. 'Sher-sherbet lemon,' he panted at it. This was the password to the hidden staircase to Dumbledore's office – or at least it had been two years ago."
- The chapter picture in the US edition for "The Rogue Bludger" shows Harry's left arm deboned. But in the story, his right arm has been deboned.
- At the end of the book, Dumbledore tells Harry that Lord Voldemort is the last remaining ancestor of Salazar Slytherin. But it should say that Lord Voldemort is the last remaining descendant of Salazar Slytherin.
- On the last page where it gives a preview of the next book, it reads: "Harry Potter has to sneak back to his third year at Hogwarts after accidentally inflating his horrible Aunt Petunia." It should say that he inflated his Aunt Marge, and that he did not have to sneak back.
Harry Potter and the Prisoner of Azkaban
- The cover of Prisoner of Azkaban (US edition) clearly depicts the night that Harry and Hermione save Sirius and Buckbeak. That night is also supposed to be a full moon, as stated in the book. However, on the back side of the cover, the moon appears to be crescent when it should be a full moon.
- It states that Harry is being waited on by the manager of Flourish and Blotts. The manager takes him to the Divination section and takes down Unfogging the Future. However, after Harry is fixated on the Death Omens book, the manager is suddenly referred to as the "assistant."
- When Mr. Weasley is arguing with Mrs. Weasley at the Leaky Cauldron, he says: "You know what Harry and Ron are like, wandering off by themselves – they've ended up in the Forbidden Forest twice!" Ron has only been in the Forbidden Forest once – to see Aragog in CoS.
- It states that "Harry and Ron led the way to the end of the train, past packed compartments, to a carriage that looked quite empty. They loaded the trunks onto it, stowed Hedwig and Crookshanks in the luggage rack, then went back outside..." Later, it states: "Harry, Ron, and Hermione set off down the corridor, looking for an empty compartment, but all were full except for the one at the very end of the train. This one had only one occupant, a man sitting fast asleep next to the window." They had just put their belongings into an empty compartment, so they didn't need to look for another. Later, it states: "A faint, tinny sort of whistle was coming from somewhere. They looked all around the compartment. 'It's coming from your trunk, Harry,' said Ron, standing up and reaching into the luggage rack." Their trunks couldn't have been in that compartment as they had stowed them in another one.
- It says: "Harry felt strangely unreal, and even more so when he saw Buckbeak a few yards away, tethered to a tree behind Hagrid's pumpkin patch." Later, however, it says: "Harry began to fumble with the rope tying Buckbeak to the fence." Here, Buckbeak is tied to a fence, not a tree.
- Throughout the series, the future Hufflepuff prefect is referred to as "Ernie Macmillan." However, in PoA, his last name is spelled "McMillan."
- It says in Chapter 13 that all of the players on the Ravenclaw Quidditch team ride on Cleansweep Sevens. However, later it states that Wood told Harry that Cho Chang (Ravenclaw Seeker) rides a Comet Two Sixty.
- It says that after his exam with Professor Trelawney, "Harry got up, picked up his bag and turned to go." But when Professor Trelawney began her prediction, the book then says: "Her eyes started to roll. Harry sat there in a panic." How could Harry be sitting when it states that he got up right before Professor Trelawney began her prediction?
- It says: "Ron crawled to the four-poster and collapsed onto it." But then when Professor Lupin comes in, it says: "His eyes flickered over Ron, lying on the floor." This cannot be, as Ron is lying on the bed.
- When the group is exiting the Whomping Willow, it states: "Black saw Snape up through the hole, then stood back for Hermione and Harry to pass." But then after Harry and Hermione turned back time and are watching their other selves, "They saw Lupin, Ron, and Pettigrew clambering awkwardly out of the hole in the roots. Then came Hermione... then the unconscious Snape, drifting weirdly upward. Next came Harry and Black." The order is different. The first time, it's Snape, Harry, Hermione, and Sirius. The second time, it's Hermione, Snape, Harry, and Sirius.
- "Hagrid turned around and headed back into his cabin, leaving the back door ajar." This allows Harry and Hermione to hear the conversation inside. Then later it says: "Hagrid's back door had opened with a bang." How can it open again, since it was never closed?
- Dumbledore was Transfiguration teacher before he was Headmaster, and Remus Lupin was born in/around 1960 (in OotP, Snape is 35 or 36, so we can make an estimate on Remus's age in PoA from that). Now in PoA, Lupin says, "I was a very small boy when I received the [werewolf] bite," and on the next page says, "It seemed impossible that I would be able to come to Hogwarts... But then Dumbledore became Headmaster..." and of course, Dumbledore allowed Remus to attend Hogwarts. Now, skip ahead to OotP. In the chapter "The Hogwarts High Inquisitor," McGonagall says she has been teaching at Hogwarts for "thirty-nine years this December." Assuming that McGonagall has always taught Transfiguration (never any other subject) at Hogwarts, and also assuming that at this point Remus would also be 35 or 36 (based on Snape's age), then Dumbledore would have been Headmaster for at least three years before Remus was born. So why did Remus say he wouldn't have been able to attend Hogwarts if Dumbledore hadn't become Headmaster after Remus was bitten?
- Slytherin Marcus Flint was stated to be a sixth year in Harry Potter and the Philosopher's Stone, yet he was still at the school in Harry Potter and the Prisoner of Azkaban (two years after his debut). J.K. Rowling admitted that this was a mistake, but gave it an explanation by saying that he had to repeat his last year due to failing his exams.
- In Chapter 16, the schedule for exams is given, and Ron and Harry ask Hermione how she is going to be in two exams at once. The thing is, for the first round of exams it is Arithmancy and Transfiguration together, and then the second round of exams includes Charms and Study of Ancient Runes. If Transfiguration and Charms are core courses, it would be impossible to include the optional courses at the same time, which means that Hermione would not have been the only student with schedule conflicts.
Harry Potter and the Goblet of Fire
- When Harry is writing to Sirius about the pain in his scar, it says he was "marveling at the fact that he hadn't thought of Sirius straight away. But then, perhaps it wasn't so surprising – after all, he had only found out that Sirius was his godfather two months ago." Harry actually found out that Sirius was his godfather about eight months before, on that day in the Three Broomsticks in Hogsmeade.
- It states that Ron, Harry, and Hermione had entered Ron's room, which is here called the "attic room." However, later it states at the bottom that one of the sounds that could be heard from Ron's room was the ghoul "in the attic." How, then, could Ron's room be considered the attic room, when there is a ghoul living above that room in "the attic"?
- It reads, "Moody had insisted on putting Harry through his paces four times in a row, until Harry could throw off the curse entirely," referring to the Imperius Curse. However, later it says, "And Harry felt, for the third time in his life, the sensation that his mind had been wiped of all thought..." Wouldn't that be the fifth time instead of the third? (Possible Explanation: The first time that Harry's mind was wiped clean was at the Quidditch World Cup, and the times that Moody tested the Imperius Curse on Harry count as one time. Therefore, when Voldemort placed the curse on Harry, it was the third time he experienced the sensation that his mind had been wiped of all thought.)
- Krum tells Hermione that she has a beetle in her hair, "but Hermione brushed away the beetle impatiently." In Chapter 37 on the train after she had captured Rita Skeeter, Hermione says, "And Viktor pulled a beetle out of my hair..." Hermione says Viktor pulled the beetle out, yet the book says that she brushed it away.
- In Chapter 35 ("Veritaserum") Dumbledore asks, "How did your father subdue you?" The book then states, "'The Imperius Curse,' Moody said." Yet the Polyjuice Potion has already worn off, and Barty Crouch, Jr. is speaking.
- Mrs. Weasley "reminisced at length about" Ogg, the gamekeeper before Hagrid. Hagrid was given the position right after he was expelled in his third year. Since this was over fifty years ago, Mrs. Weasley wouldn't remember another gamekeeper.
- Fudge says, "You are prepared to believe that Lord Voldemort has returned, on the word of a lunatic murderer, and a boy who... well..." Shouldn't he have said "You-Know-Who" or "He Who Must Not Be Named" like he usually does?
- When Harry and Voldemort's wands met and created the "Priori Incantatem," the ghosts of those that Voldemort killed came from his wand in reverse order, from Cedric until Lily. But she was supposed to come out before James, as she was killed last protecting Harry. This was changed in later editions.
Harry Potter and the Order of the Phoenix
- The cover of Order of the Phoenix (US edition) shows Harry in the Department of Mysteries holding his wand in his left hand. However, it is clearly stated that his right arm is his wan arm.
- On page 1, Harry is lying in Aunt Petunia's hydrangea bush, but later he recalls that "someone magical had been near him as he lay among Aunt Petunia's dying begonias..." (Possible Explanation: Aunt Petunia may have had a variety of plants and flowers in her garden.)
- It says: "Harry stepped into the shadow of a large lilac tree and waited." But lilacs grow on bushes, not trees.
- The description of 12 Grimmauld Place states: "The silver door knocker was in the form of a twisted serpent. There was no keyhole or letterbox." However, it clearly shows on the title page (the drawing of Snuffles exiting number twelve) that there is a keyhole (in the US edition).
- In Chapter 9 ("The Woes of Mrs. Weasley"), it says: "He pretended to be rummaging for something while Hermione crossed to the wardrobe and called Hedwig down. A few moments passed; Harry heard the door close but remained bent double, listening... He straightened up and looked behind him. Hermione and Hedwig had gone. Harry hurried across the room, closed the door..." But Harry had already heard the door close.
- Harry is able to see the Thestrals at the beginning of the book. It is later explained that you can see them after you have seen death. Harry had seen the death of his mother and possibly his father before he saw Cedric Diggory die, so why didn't he see the Thestrals before? (JKR's response: You can't see them until the death "sinks in.")
- It says: "The horse was there in front of him, gleaming solidly in the dim light issuing from the station windows behind them, vapor rising from its nostrils in the chilly night air." Before this line, Harry tells Ron that he can see the skeletal horses and Ron can't see them. However, even if Ron couldn't see the horses, he should have been able to see the vapor rising from nowhere.
- Ron groans about their schedule. "History of Magic, double Potions, Divination, and double Defense Against the Dark Arts..." Shortly after, Harry and his classmates suffer "an hour and a half's droning." Later, Snape informs the class that they have "an hour and a half" to complete their assignment. It was a regular History of Magic lesson, yet it lasted the same amount of time as double Potions.
- In Chapter 13 ("Detention with Dolores"), Professor Grubbly-Plank states: "I want a sketch from each of you with all body parts labeled by the end of the lesson." The inconsistencies are noticeable at the end of that class; for example, it says: "When the bell echoed distantly over the grounds, Harry rolled up his blood-stained Bowtruckle picture and marched off..." Then, Harry says that they all (specifically Ron and Hermione) have tons of homework, including to "finish the Bowtruckle drawing," and again it's mentioned later, and then again when Harry even skips lunch to finish it. Wasn't it due at the end of the original class, therefore not being homework?
- It says "...but Harry pulled out his Charms books and set to work on finishing his essay..." However, the excerpts from the Charms book have nothing to do with Charms – they sound like potion ingredients: "Therefore much used in Confusing and Befuddlement Droughts..." Then, after his conversation with Dobby, "He [Harry] bent and picked up his Potions book. He'd have to try and finish the essay tomorrow." It appears that Harry's Charms essay magically transformed into a Potions essay.
- In Chapter 22 ("St. Mungo's Hospital for Magical Maladies and Injuries"), it says: "There was a flash of flame in the very middle of the office, leaving behind a single golden feather that floated gently to the floor." But the next paragraph reads: "'It's Fawkes's warning,' said Dumbledore, catching the feather as it fell." Dumbledore couldn't have caught the feather – it was already on the ground.
- In Chapter 24 ("Occlumency"), it says: "'That bossy woman up front 'oo got on with you, she's given us a little tip to move you up the queue. We're just going to let Madam Marsh off first, though–' There was more retching from downstairs, followed by a horrible spattering sound. 'She's not feeling 'er best.'" Nowhere did it say that they had heard retching, so why did it say "more retching"?
- The illustration in the US edition shows Fred and George flying into a night sky with a very full moon. However, it says: "Fred and George wheeled about to tumultuous applause from the students below and sped out of the open front doors into the glorious sunset."
- In Chapter 29 ("Career Advice"), Professor McGonagall seems to make a mistake. She tells Harry that he will need a minimum of five NEWTs, but only four are listed: Defense Against the Dark Arts, Transfiguration, Charms, and Potions. What happened to the fifth subject?
- In Chapter 30 ("Grawp") at the Gryffindor/Ravenclaw Quidditch match, it says: "They [Harry and Hermione] found seats in the topmost row of the stands." Later on, when Hagrid comes to take them to see Grawp, it says: "Apparently he [Hagrid] had squeezed his way all along the row behind." How can that be if Harry and Hermione were in the top row?
- In Chapter 31 ("OWLs"), when Harry is taking his practical Astronomy exam around midnight, the book says that he sees Orion and Venus from his position on the Astronomy Tower. However, Orion cannot be seen at night in the month of June in the northern hemisphere, and Venus can never be seen at midnight. (Thanks to Vicki.)
- While Harry is vanishing an iguana for his practical Transfiguration exam, the book says that Hannah Abbot "lost her head completely at the next table and somehow managed to multiply her ferret into a flock of flamingos..." However, on the previous page, we are shown that the students were called in in alphabetical order: "Parkinson, Pansy – Patil, Padma – Patil, Parvati – Potter, Harry." If they were all called alphabetically by last name, why are Abbot and Potter together?
- In Sorcerer's Stone, it says that Percy had a silver prefect badge. However, in Order of the Phoenix, it says that the prefects' badges are scarlet and gold.
- In Chapter 37, Harry is upset that he did not get the chance to ask Sirius if he thought Harry flew as well as his father, James, did. Meanwhile, in Prisoner of Azkaban, Sirius had already discussed the similarities between Harry and James's flying as he was trying to declare his innocence when he told Harry, "...I journeyed north and slipped onto the Hogwarts grounds as a dog. I'd been living in the forest ever since, except when I came to watch the Quidditch of course. You fly as well as your father did, Harry." Harry would never have needed to ask Sirius in Order of the Phoenix because Sirius had already told him in Prisoner of Azkaban.
Harry Potter and the Half-Blood Prince
- The cover illustration portrays Dumbledore with a normal-looking right hand, but the text makes it clear that it is Dumbledore's right hand and arm that are blackened and shriveled, and that are still in such condition at the precise moment depicted by the cover illustration.
- When Dumbledore and Harry enter Horace Slughorn's house, something "darkly red and glutinous was spattered over the wallpaper." Later, when asked what kind of blood it was, Slughorn explains: "On the walls? Dragon... My last bottle, and prices are sky-high at the moment." However, in OotP, when Hagrid finally returns in Chapter 20, he is nursing his bloodied face with a green-tinged steak of dragon meat. "He picked up the steak and slapped it over the left side of his face. Greenish blood trickled down into his beard as he gave a soft moan of satisfaction."
- Slughorn says: "One tiny bottle of Felix Felicis enough for twelve hours' luck. From dusk 'til dawn, you will be lucky in everything you attempt." But then later, Harry says: "I don't reckon I'll need all of it, not twenty-four hours' worth..."
- It states: "Malfoy looked rather as he had done the time Hermione had punched him in the face." However, in PoA, it says that Hermione "...had slapped Malfoy around the face with all the strength she could muster."
- In PoA, it states that: "The exam results came out on the last day of term." It continues: "Percy had got his top-grade NEWTs; Fred and George had scraped a handful of OWLs each." But in HBP, Dumbledore says that the OWL results are expected sometime later today – "today" meaning sometime during the summer holidays, and not while the students are still at Hogwarts. It is possible that the exam results aren't released at the same time every year.
- In HBP, Dumbledore states that Gryffindor's sword is the only relic left of Godric Gryffindor's – but the Sorting Hat belonged to Gryffindor as well.
- In the Jim Dale audiobook, it states near the end of Chapter 5 that Hermione got ten Outstandings. In the book, it is stated that Hermione received 9 Outstandings and 1 Exceeds Expectations in Defense Against the Dark Arts. (Thanks to Beth.)
- In the book, it states "They now joined the spectators in the stands to watch the selection of their last team member" (Chapter 11). However, the audiobook states "They now joined Katie, Demelza, and Ginny in the stands to watch the selection of their last team member". The Chasers participate in the Keeper try-outs, so they couldn't have been sitting in the stands. (Thanks to Beth.)
Harry Potter and the Deathly Hallows
- The Elder Wand was supposed to be unbeatable, but Dumbledore defeats Grindlewald to win it
- In Chapter 9, Hermione, Ron, and Harry escape the Burrow to Tottenham Court Road where they are followed to a small, shabby cafe by two Death Eaters. The Death Eaters are hit by spells by Harry and Hermione, and they have to decide what to do with them. Harry suggests they just wipe their memories, and Hermione says she's never done this. But earlier in Chapter 6, Hermione explains that she has modified her parents' memories and sent them to Australia to keep them safe.