She is played by Ana Gasteyer.
Role in the film
As the schoolteacher, Signora Giovanni is breaking up a fight between Pinocchio and one of her other students. When Geppetto arrives, she tells him to take Pinocchio home. She tells him the way Pinocchio was acting cannot be tolerated, and that being made of pine (Geppetto says pine scratches; he's made of birch) does not exempt him from following the rules. At one point, Geppetto compliments her bun, much to her gratitude.
Then he asks her what the trouble is. She tells him it is Pinocchio due to imitating all the other children which created the stir that was happening. Geppetto asks Pinocchio if that's true. The other student says that everything he did, Pinocchio (repeated)... Pinocchio repeats that and the hand motion. "See?" asks the other boy. Again, Pinocchio repeats that. Geppetto tells him to stop that. Pinocchio attempts to explain why, but he tells Pinocchio he owes Signora Giovanni an apology. Again, Pinocchio protests, trying to say he was just doing what he was told, but Geppetto won't allow an excuse. He tells him to just tell her he is sorry. He apologizes, and Geppetto asks him if that was hard. So he says he'd best be on his way, but Signora Giovanni reminds him to take Pinocchio home. She then warns him to be careful because "boys like that" often end up on Pleasure Island. As Geppetto angrily takes Pinocchio home, Signora Giovanni gets the other children back to class.