Continuity mistake: When the Darlings arrive home the dog pound carriage's lights are out. A shot later they are lit.

Continuity mistake: From left to right, in the room where Tramp chases the rat there's a chest, a couch, a huge window with fallen curtains on a table. When the rat is killed the window disappears, and thus the curtains over the table. After aunt Sarah locks Tramp, the window reappears and the curtains are back on the table.
Continuity mistake: After Tramp brings Lady a bone, he drops it on the floor and the bone suddenly disappears. Later, when Lady recounts Tramp's girlfriends not only does the bone reappear, but a bowl magically appears on the ground.
Continuity mistake: During the spaghetti dinner scene, the size and text of the sign to the right of the door keeps changing in every single shot.
Continuity mistake: When Tramp arrives at Tony's restaurant, on top of the big crate with vegetables there is a smaller box. Depending on the shot, the box is solid wood, or has wooden planks with vegetables coming out in between them.
Continuity mistake: When Tramp arrives at Tony's, there's a crate with four rows of vegetables. A shot later it has three rows and, a shot later, it changes back to four.
Continuity mistake: Tony kneels by some crates and greets Lady. From the opposite angle he disappears.
Continuity mistake: When Lady and Tramp arrive at Tony's, she stands behind some crates and the place is fully lit. A shot later, the place is in the shadows.
Continuity mistake: When Trump ties Lady's leash to the branch in the log, the leash is tight, but a shot later from a different angle it's loose.
Continuity mistake: When the beaver makes a gouge in the log, the distance to the leaves behind decreases significantly between shots.

Continuity mistake: After the crocodile scene, Lady and Trump jump away and land on a narrow street inches away from the hyena cage. After the hyena stops laughing, the place is completely different: Wide and with a fountain in the middle. Lady is sitting still so they couldn't have gone somewhere else in between shots.
Continuity mistake: When Lady sneaks to see how Mrs. Darling is putting the baby asleep before she enters the room, there's a couch in the back of the room. When Lady enters the couch becomes a table.
Continuity mistake: During Lady and the cats' fight, before they break the curtain an easel with a framed painting on the left suddenly appears between shots.
Continuity mistake: When the cats attack Lady a green curtain falls on her. When aunt Sarah arrives the curtain is red.
Continuity mistake: When the cats climb up the wooden closet before they attack the fish, the closet is made of carved wood and has two glass doors. In the following shot the wood is plain, doors and glass are gone and there's now a green curtain.
Continuity mistake: When the cats knock down the tablecloth on the piano, the tablecloth changes positions between the first and second shot.

Continuity mistake: The first time we meet Tramps he is brown with a light brown belly. When he has breakfast at Tony's he is tan coloured. After Lady tells about the baby he becomes gray coloured. When the movie ends he is dark grey coloured.
Continuity mistake: Before Lady and Tramp have dinner the menu on the table disappears. Tony couldn't have fetched it because it never appears in his hands when he's ordering the spaghetti.
Continuity mistake: When Tramp and Lady arrive at Tony's, check the back part of the kitchen towel next to Tony and you'll notice that it folds different between shots.
Continuity mistake: Before the beaver starts to roll down the hill the sawdust next to the first gouge he made in the log disappears.