Katherine Willis is an American actress and producer, best known for her roles as Myrtle Hale in Killers of the Flower Moon (2023), Diana Lord in Tell Me Your Secrets (2021), and Joanne Street in Friday Night Lights (2006). She is also known for her work on: NBC's The Blacklist (2013), HBO's The Leftovers (2014), USA Network's Queen of the South (2016), and the Nat Geo miniseries The Long Road Home (2017).

Katherine started acting in theater when she was 12 yrs old. She attended Brigham Young University on a theater scholarship. Born on the South Pacific island of Tonga, and the fourth of seven children, her childhood was spent in rural Missouri on a 200 acre farm.