William Thomas Hader Jr. (born June 7, 1978) is an American actor, voice actor, comedian, writer, producer and director. He rose to fame as a cast member on the NBC variety series Saturday Night Live (2005–2013) for which he received four Primetime Emmy Award nominations and a Peabody Award.
Hader has had supporting roles in the films Superbad (2007), Tropic Thunder (2008), Forgetting Sarah Marshall (2008), Night at the Museum: Battle of the Smithsonian (2009), Men in Black 3 (2012) and leading roles in The Skeleton Twins (2014), Trainwreck (2015) and It Chapter Two (2019) as an adult Richie Tozier. He has voiced lead characters in the Cloudy with a Chance of Meatballs franchise (2009–2014), Inside Out (2015), the Angry Birds films (2016, 2019), Sausage Party (2016), Ralph Breaks the Internet (2018) and supporting roles in Turbo (2013), Monsters University (2013) and Finding Dory (2016).
During his time on Saturday Night Live, Hader became known for his impressions and his character Stefon in the Weekend Update segments. He is the co-creator, writer, and producer of the IFC mockumentary comedy series Documentary Now! (2015–present), in which he stars in alongside Fred Armisen. In 2018, Hader created and began starring as the titular assassin in the HBO dark comedy series Barry, which earned him two Emmy Awards for Outstanding Lead Actor in a Comedy Series and consecutive nominations for Outstanding Comedy Series, Outstanding Directing for a Comedy Series and Outstanding Writing for a Comedy Series for its first two seasons.