Movies:
* The Darkest Minds (2018) - Played the role of "Lily"
* The Kissing Booth (2018) - Played the role of "Rachel"
* The Kissing Booth 2 (2020) - Reprised her role as "Rachel"
Television:
* The Magicians (2016-2020) - Played the recurring role of "Julia's Doppelgänger"
* The Good Doctor (2017) - Guest-starred as "Young Sarah" in the episode "Intruders"
* Supernatural (2018) - Guest-starred as "Mary Winchester" in the episode "The Spear"
* The 100 (2019) - Guest-starred as "Josie" in the episode "The Gospel of Josephine"
* The Haunting of Hill House (2018) - Played the role of "Young Shirley"
* The Haunting of Bly Manor (2020) - Reprised her role as "Young Shirley"
Other Projects:
* The Kissing Booth: Reunion (2023) - Reprised her role as "Rachel"
Please note that this list may not be exhaustive and may not include all of Katelyn Vanier's projects. It's also important to note that her role in some of these projects may be very brief or uncredited.
For a more complete list of her acting credits, you can refer to websites like IMDb or other online movie databases.