1. When Ariel first meets Max and he gives her a big slobbery kiss, you can see her wiping the kiss from her face on the wrong side.
2. In the dinner scene, you can see the covers on the plates have a crescent-shaped handle. The handles are a different style when Sebastian runs across the table moments later.
3. When Ariel stops Eric and Vanessa's wedding, she arrives at the ship without shoes. However, she's wearing shoes in the same scene immediately after getting her voice back.
4. When Ariel first sees the dinglehopper in the shipwreck, it has four tines. When she picks it up, it has three.
5. During the beginning of "Les Poissons," Chef Louis does not have buckles on his shoes. Gold buckles appear the very next time his shoes are shown.
6. During "Kiss the Girl," Ariel's hair is half up and half down for the whole song, but her shadow reflects that it's in a pony tail.
7. When King Triton first enters on his dolphin chariot, he is holding two separate reins. When he lets go of the reins moments later, it has instantly changed into one continuous rein.
8. When Chef Louis apologizes for his ruckus, the buttons on his shirt are on the right-hand side. In the next frame we see him in, his buttons have switched to the left-hand side.
9. In the scene where Ariel and Flounder explore the shipwreck, Flounder gets stuck in the porthole. From the back, his fins are clearly stuck outside of the porthole. When the view changes to the inside of the ship, his fins are shown already through.
10. When King Triton bargains with Ursula, his crown has five spokes. As soon as Ursula transforms him, his crown drops and suddenly has seven spokes.
11. When Chef Louis throws flour onto Sebastian in "Les Poissons," the sauce he is sitting in is brown. In the next frame, this sauce has turned completely white. Flour wouldn't change the color that drastically.
12. King Triton completely obliterates the statue of Prince Eric when he discovers Ariel's grotto. Right after he leaves, we can see the entire face of the statue intact despite being blown up moments before.
13. During Eric and Vanessa's wedding ceremony, the bookmarks in the priest's bible switch places and colors between frames.
14. After King Triton destroys Ariel's grotto, she's seen crying on a rock near a broken vase and a plank of wood. However, in the wide shot of this same scene, the wood is gone, the vase is different, and the rock formation she's crying on has changed.
15. When Vanessa is getting ready for her wedding and singing about her evil plan, she steps on a perfume bottle that wasn't on her vanity five seconds before.
16. The porthole that Scuttle lands at to spy on Vanessa changes design between the time that we see him fly to it and the time that we see him fly from it.
17. Finally, when we first meet Max, the color of his paws change from white to gray between shots. They are white for the rest of the movie.
TBH, I think I can see past these tiny mistakes because this movie is still one of my absolute favorites.
H/T Movie Mistakes