Christopher Lowell is an American actor. He is best known for playing the roles of Stosh "Piz" Piznarski in the television series Veronica Mars (2006–2007), William "Dell" Parker in the television series Private Practice (2007–2010), Sebastian "Bash" Howard in the television series GLOW (2017–2019), and Jesse Walker in How I Met Your Father (2022-2023). He has also appeared in films, notably Up in the Air (2009), The Help (2011), and Promising Young Woman (2020), all of which were nominated for the Academy Award for Best Picture.