Continuity mistake: When Princess Mia takes the chicken out of the basket and it gets loose, we see the chicken run away, followed by Princess Mia running after the chicken, and finally the palace guard falling amid a number of boxed, gift-wrapped presents. The only boxed presents that were visible in any of the previous shots were already on the floor and there were none anywhere close to the palace guard that he could have knocked down as he fell.
Continuity mistake: When Princess Mia is announced at her birthday ball, she waves with her right hand and then waves so enthusiastically with her left hand that her bracelet flies off backward. We see it flying fairly high up judging by the door in the background. But when the doorman catches it, its much lower then it should have been (from the previous scene) with a much lower and flatter trajectory.
Continuity mistake: In the fan lesson, when the Queen puts the fan over her face, it shows the back, but when it cuts back to her, it is showing the front. This happens twice. (00:37:15)
Continuity mistake: In the scene where Nicholas is giving the Queen a chocolate cake in the kitchen, flowers suddenly appear on the table and behind the queen.
Continuity mistake: When Nicholas serves the Queen a chocolate cake, the position of the items on the table changes position between shots. For example, in the close-up of the cake, there's a tablecloth with flowers next to it. In the other shots of the table, they're much further away from the cake. (00:43:05)
Continuity mistake: The scandal video that Elsie shows is not consistent with what the man in the boat with a video camera could have really shot because of the length of time he ducks down into the boat and then is seen sitting up and then bringing out his video camera and supposedly "starts" shooting. If he was shooting before he ducked down and then reappeared, there would be a big gap of Princess Mia waking and sitting up and looking at Nicholas and then at the cameraman and then back at Nicholas. If he didn't start shooting until we actually see him raise the camera up, then the video replay in Princess Mia's room couldn't have had everything on it that is shown.
Continuity mistake: In the scene where Princess Mia is inspecting the troops, there is a shot of Lord Devereaux watching the procession. The color of his tie is black. Immediately afterwards, when he goes to comfort Princess Mia in the barn, his tie is red. The mistake was acknowledged by director Gary Marshall during the commentary on the DVD.
Continuity mistake: When Princess Mia is being crowned Queen, we see Charlotte at the top of the left set of stairs, the ones Queen Clarisse just descended. We see Charlotte's legs at the top of the stairs until they go out of frame as Mia turns around to stand in front of throne. The next shot is of Nicholas and CHARLOTTE. Wow, how did she get down there so fast?
Continuity mistake: When the newly engaged royal couple is presented to the Genovian public, they walk out onto a balcony between two royal palace horn players. Just as the royal couple begins to wave, the horn players lower their horns. The view is switched to a long shot of the front as the royal couple is waving and the horns are back up. They remain up near the players mouths for the rest of the scene even though they don't play anymore.
Continuity mistake: During the parade scene, there is a man with a full beard/moustache (sort of a reddish brown) with a black hat, white shirt and black jacket that I believe we first see handing Genovian flags to Charlotte before she tries to get Viscount Mabrey to wave one. This man then goes to stand behind the head of the black man sitting next to Viscount Mabrey. Next, after the parade starts, we see Elsie and Miss Genovia at a table and right above and a little to the left of Elsie's head we the same bearded man. We see some parade shots and then another shot of Elsie with the bearded. Then we see Carolina shots and the parade being stopped. The next shot is of Andrew, Nicholas and Viscount Mabrey and just above and a little to the left of Mabrey's head is our bearded man. Then Elsie ends her commentary with the bearded man's chest and flag in visible in the background. Unless he is a twin like our palace guard, he certainly gets around very fast.
Continuity mistake: In the scene where Andrew Jackoby gives Princess Mia the engagement ring, she opens the film canister and the shot shows her emptying the ring into her left hand which reveals a freckle on her pinky finger. When the shot returns to her hand the freckle is gone. (00:29:30)
Continuity mistake: After Nicholas has kissed Princess Mia in front of the fountain, we can see the front of his hair is messed up, probably from the brim of her hat. As they walk around the fountain, his hair is still messed up. As the scene angle changes as Nicholas says, "Maybe I am," his hair is now fixed and not messed up as in previous shots.
Continuity mistake: When Nicholas is trying to get Princess Mia's attention, he is throwing pebbles at her open window. She sticks her head out of the window. The next shot is Nicholas throwing another pebble and acting like he hasn't seen her. We hear the pebble click against glass but if it actually did, it would have had to almost hit Princess Mia but she acts as though nothing has happened.
Continuity mistake: In the chicken scene, as we see Tiny starting to hand the chicken in a basket to Princess Mia, in the background are Brigitte and Brigitta. They are behind the palace guard and to the left of Charlotte and the housekeeper. When we hear Princess Mia say, "May I?", the scene show Charlotte (and the housekeeper) but now Brigitte and Brigitta are behind Charlotte.
Continuity mistake: When Princess Mia stops the parade and goes over to talk to Carolina, we see Carolina's hair from a back, side view and it is pretty messy. Then we see a front shot and her hair is very neatly tucked behind her ear with her braid hanging neatly by itself. Then we see a quick back shot as Princess Mia asks the boys' names that are messing with Carolina and we can't see her ear but the hair over it is very messy. Back to a front shot and it is neat again until Carolina tells Princess Mia that the boys were tugging on her braid and she demonstrates by pulling on her braid. (00:55:40)
Continuity mistake: When Viscount Mabrey and Nicholas are at Mabrey's home, plotting Nicholas' next move, Mabrey is sitting on a sofa with his legs crossed at the knee and a magazine is across his lap. Mabrey's right hand is holding the top of the magazine. Mabrey points his left index finger at Nicholas and asks if he remembers who his father named him after. The shot switches to Nicholas saying that he was named after Grandfather Nicholas. It then goes immediately back to Mabrey starting to get up but now, in just a second or two, Mabrey's feet are both on the floor and the magazine is folded up and held in his right hand.
Continuity mistake: In the DVD viewing when Nicholas is helping Mia with her archery, you can see the sun shining on them. However, between shots they appear to be in the shade because the sunshine is not there. (01:09:25 - 01:10:15)
Continuity mistake: When Lionel is speaking to the Queen, she introduces him to the housekeeper and her two ladies' maids; they are standing in front of the window directly to the right of the Queen. Lionel leans over to tell the Queen he would take a bullet for her and she says that interns don't even want to get her tea. Joseph grabs Lionel and we see the window where the housekeeper and maids were just standing but they have disappeared.
Continuity mistake: Right after Princess Mia and Andrew meet and are walking on the beach, a shot of them shows Princess Mia's scarf around her neck from the front with the ends blowing very visibly out to the back. Then it cuts to the press corps and then back to Princess Mia and Andrew. You can see her scarf is now on wrapped around the back of her neck with the ends her coat. Then we see her hair move first as her scarf is pulled (blown off?) from a string or wire pulls it off from the back.