Kate O'Flynn (born 1986) is a British actress known for her performance in National Theatre's production of Port, for which she received a Critics' Circle Theatre Award in 2013, as well as starring roles in plays A Taste of Honey in 2014, and The Glass Menagerie, for which she was nominated for a Laurence Olivier Award for Best Actress in 2017.

She has appearances in the films Up There (2011) and Mr. Turner (2014), and television series such as Kingdom (2009), Landscapers (2021), Death in Paradise (2022), My Lady Jane (2024), and Widow's Bay (2026-present).