William Emerson "Will" Arnett (; born May 4, 1970) is a Canadian actor, voice actor, comedian, and producer. He is best known for his role as BoJack Horseman in the Netflix series of the same name and George Oscar "Gob" Bluth II in the Fox/Netflix series Arrested Development (2003–2006, 2013, 2018–2019), receiving a nomination for Primetime Emmy Award for Outstanding Supporting Actor in a Comedy Series. He has appeared in films such as Blades of Glory (2007), Hot Rod (2007), When in Rome (2010), Teenage Mutant Ninja Turtles (2014), and Teenage Mutant Ninja Turtles: Out of the Shadows (2016). His performance as Devon Banks in 30 Rock earned him four Primetime Emmy Award for Outstanding Guest Actor in a Comedy Series nominations.
His deep, smooth baritone voice has landed him prolific roles within animation, including Ice Age: The Meltdown (2006), Ratatouille (2007), Horton Hears a Who! (2008), Monsters vs. Aliens (2009), Despicable Me (2010), The Nut Job (2014), and as Batman in the Lego Movie franchise. He also served as an executive producer and voices the titular character of the Netflix series BoJack Horseman (2014–2020), for which he won an Annie Award at the 46th Annie Awards. His involvement with The LEGO Group continues as Fox Network announced him as the host of their show LEGO Masters, which premiered on February 5, 2020.
He is also known as William Emerson Arnett and Arnett, Will.