Continuity mistake: When Harry, Ron, and Hermione are in the staircases, watch the pictures on the right: they are not moving, but when the camera changes all the pictures are moving. (01:00:50)
Continuity mistake: In the scene where the new students are walking to their rooms, there seems to be a whole lot more new students then there was in the sorting hat ceremony. (00:41:40 - 00:48:05)
Continuity mistake: In the chess scene, when Ron falls off the horse, he is lying on his side on the floor with one knee bent so that one foot is higher than the other. When Harry and Hermione run over to check on him, one foot is on top of the other. (02:05:15 - 02:06:00)
Continuity mistake: The very first scene where you see Hagrid on his motorcycle, he comes down and, from his position, you can tell he's gonna land way past the first house on the set. The next shot you see him touch down in front of that house. (00:02:15)
Continuity mistake: Malfoy has one tooth that is notably crooked. If you watch carefully, you'll see that it changes sides throughout the film. (00:40:55 - 01:43:50)
Visible crew/equipment: When Oliver Wood is explaining Quidditch to Harry, he struggles to put the Bludger back in the trunk. You can see a rod under the trunk lift and shake it, so the Bludgers appear to be moving on their own. (01:05:55)
Continuity mistake: When Harry, Ron and Hermione are running to Hagrid's hut to tell him they know about the stone (just before they see Norbert) Hermione's hair is very long, but by the time they get inside his hut and take off their cloaks, her hair is much shorter. (01:38:40 - 01:39:25)
Other mistake: When Harry, Ron, and Hermione go after the Philosopher's Stone, the harp stops playing. They look up at the dog, but its shadow is cast on the ceiling above them as well as on top of them. This shows there were lights behind the 3. (01:56:00)
Other mistake: In the scene where Ron and Harry are on the train to Hogwarts, the window to the compartment is open. We know this because the chocolate frog jumps out the window and is swept away by a pretty strong wind. Since the window is indeed open, shouldn't there be a visible breeze thoughout the compartment? (00:35:50)
Continuity mistake: When Harry sneaks into the restricted section of the library with his lantern, he puts the lantern down on the ledge and the light doesn't even flicker, you can tell it's a sort of lightbulb, not a candle. (01:29:10)
Continuity mistake: In the scene in the library's restricted section, Harry puts down his cloak and then his lamp. The lamp is several inches away from the cloak. When Filch enters Harry grabs the cloak and suddenly the lamp is now on top of the cloak, causing it to fall. (01:29:10)
Continuity mistake: When Professor McGonnagall is talking to the children before their sorting, you can tell when the camera is on her that the lighting is candle-like (note the flicker). When the camera cuts to the children, there is no flicker (check out Hermione). (00:39:50)
Continuity mistake: When all of the letters are arriving from Hogwarts at the Dursleys' house, it is obvious that the ones flying around the room are just single pieces of paper and not thick envelopes containing letters. (00:11:25)
Continuity mistake: In the scene where the pupils are waiting on the stairs before being sorted into their houses, Malfoy speaks to Harry and is clearly at the top of the stairs. However as the pupils go into the dining room, Malfoy is nowhere to be seen in at least the first 30 pupils. (00:41:15)
Other mistake: In the scene near the end of the movie where Harry boards Hogwarts Express to go home, Hagrid stands on the platform and waves goodbye. He is wearing a coat and looks huge, as usual, but you can see when he waves, that his hand seems rather small compared to the rest of his huge frame. (02:23:15)
Continuity mistake: When Harry and Ron are sat on the train, Ron's hair begins with a centre parting, but soon changes to a side parting. (00:32:59)
Continuity mistake: When the three heroes first go into the forbidden corridor and are spotted by Filch's cat, they run away, through the large horizontal corridor which must be at least 40 metres long (since we are given two long shots of it and neither of them connects by any physical object). They hide behind a wooden door which they close afterwards. When Filch looks in the other end of the corridor then leaves and we hear a very silent click, Hermione says 'Filch is gone.' The door they're behind does not seem to be open at all, and even if it is open a bit on the right side, Hermione's on the left side of it so she can't see whether Filch is gone or not. And can you hear a silent click of a closing door from forty metres? (01:01:45)
Continuity mistake: When Hagrid drags the Christmas tree into the castle, in the first shot there is no snow on his hair, although he has supposedly been outside for some time. When the camera angle changes his hair is now covered with snow. (01:25:10)
Visible crew/equipment: Hagrid surprises Harry with the box of birthday cake and Harry opens the box. In the close-up of the cake, as Harry holds the box with his left hand and moves the blue string with his right hand, a crew member's finger is visible under the box, over Harry's left shoulder. Obviously it is someone holding the box underneath, while Harry holds it with one hand. (00:14:10)
Continuity mistake: When Harry and Ron rush into the bathroom after the troll to rescue Hermione, they push open the closed doors, but wouldn't they be open from when the troll went in there moments before? The doors can't have closed after the troll as when Harry and Ron push open the door, it stays open. (01:09:55)
