In Butter, Brooke makes a butter sculpture with a red "A" painted in the middle.
Crazy, Stupid, Love: Robbie Weaver does a book report on The Scarlet Letter, but due to being angry that his crush Jessica Riley rejected him, goes on a long rant that the "A" stands for "Asshole" and starts calling everybody assholes, getting him in trouble.
Easy A: The plot of the movie is Olive, the main character, pretending she lost her virginity while her best friend was away for the weekend, and then being targeted by a group of Christian teens led by Marianne. This escalates when a closeted classmate asks her to pretend she had sex with him. Eventually, thanks to Marianne, Olive is targeted as a slut, which Olive embraces at first, even wearing a letter "A" sewn into her dress, since her class is reading The Scarlet Letter (there's also a Take That! against the movie version starring Demi Moore).
In There's More Than One Way Home, Anna thinks that if she had to wear a scarlet "A" on her chest, people might think it was a monogram.
Eye Contact: In high school, Cara read The Scarlet Letter to Kevin, who had trouble reading. She found the descriptive passages excruciatingly dull and tried to abridge the book for him.
In The Nowhere Girls, Rosina compares Lucy's social status after her rape to Hester Prynne and asks Grace if she's read The Scarlet Letter. Grace says, "I never read it. It was banned from my school library."
In The Mermaid's Daughter, Kathleen's father Robin is writing an opera based on The Scarlet Letter. While he was reading the book, Harry kept interrupting Kathleen's phone calls with him to ask him what chapter he was on and what he thought of it.
Veronica Mars: In the third season episode "There's Got to be a Morning After Pill", when Veronica tries to find out who slipped a classmate RU86 (which caused the classmate to miscarry), she goes to meet the classmate's father, a preacher, and gives her name as "Hester".