Librarian

The Librarian is a minor character who we first meet in the Season One episode Bad Reputation. She is seen as cranky and moody, a typical stereotype of librarians, yet she does soften up at times, and is supposed to appreciate some singing. In the credits, she is always listed as "Ancient Librarian." She has only had one speaking line, which was in Bad Reputation.

She was portrayed by the late actress Jean Sincere.

Bad Reputation
She is seen watching Artie, Tina, Mercedes, Kurt, and Brittany's performance of U Can't Touch This. She then asks if the kids would perform that for her Sunday Service and commented that it was 'very cute'.

Duets
She tells Tina and Mike to be quiet when they are fighting in the library.

Silly Love Songs
She warns Quinn and Sam to shush when they are arguing about the Kissing Booth.

Glee, Actually
She doesn't appear in this episode, but Rachel is seen instead of her during Artie's Dream. According with it, if New Directions hadn't existed, Rachel would have become the new librarian after graduating.