Movies:
* Pitch Perfect (2012): This musical comedy launched her into mainstream recognition, where she played the sassy and talented Stacie.
* Pitch Perfect 2 (2015): Knapp reprised her role as Stacie in the sequel, which was even more successful than the first film.
* Project X (2012): This raucous party comedy featured her as the memorable character of "Jenna."
* The Perks of Being a Wallflower (2012): She appeared as a supporting character in this acclaimed coming-of-age drama.
* The Age of Adaline (2015): This romantic fantasy film starred Blake Lively and Harrison Ford, and Knapp played a smaller role.
* So Undercover (2012): This Disney Channel movie saw Knapp as the lead character, a college student who goes undercover as a pop star.
* Cougar Club (2013): This comedy was another one where she played a major role.
* The Wedding Ringer (2015): Knapp had a supporting role in this comedy starring Kevin Hart.
* The Last Ride (2018): A thriller that offered her a more dramatic part.
* The Sleepover (2020): A family comedy released on Netflix where Knapp played the role of "Alice."
* The Killer Next Door (2023): A horror thriller where Knapp played "Jamie."
* The First Time (2012): A teen romantic comedy that saw her alongside Britt Robertson and Dylan O'Brien.
Television:
* One Tree Hill (2008-2012): Knapp appeared in several episodes of this popular teen drama series.
* The Vampire Diaries (2010-2017): She played the recurring role of "Pearl," a vampire who was a member of the Travelers group.
* Pretty Little Liars (2010-2017): Knapp had a guest-starring role in the suspenseful teen drama.
* The In Between (2021): A Netflix drama series where Knapp had a recurring role.
* The Clearing (2023): A Hulu miniseries with Knapp playing "Ashley."
This list includes some of her more notable projects, and there are many more movies and TV shows that she has starred in or had guest appearances. You can find a full list of her filmography on websites like IMDb.