Nancy Bletheim is the William McKinley High geometry teacher who made her debut in The Purple Piano Project. She begun her teaching job at the school in 1969. She is seen to be antagonistic about the art kids which leads Sue to launch her campaign against arts. She is portrayed by Barbara Tarbuck.
She is first seen after Sue gets mad with glee club members, Tina Cohen-Chang and Mike Chang for playing "Chopsticks" in the hallway on a purple piano. She introduces herself to Sue and informs her that she has been working at the school for 42 years. She also states that she dislikes Art kids and believes them arrogant. So far, she has only been seen in this episode on Glee.