Stellan John Skarsgård (; born 13 June 1951) is a Swedish actor. He is known for his roles as Jan Nyman in Breaking the Waves (1996), Captain Tupolev in The Hunt for Red October (1990), Prof. Gerald Lambeau in Good Will Hunting (1997), Bootstrap Bill Turner in Pirates of the Caribbean: Dead Man's Chest (2006) and Pirates of the Caribbean: At World's End (2007), Bill Anderson in Mamma Mia! (2008) and the sequel Mamma Mia! Here We Go Again (2018), Commander Maximilian Richter in Angels and Demons (2009), Martin Vanger in The Girl With the Dragon Tattoo (2011), Dr. Erik Selvig in the Marvel Cinematic Universe films Thor (2011), The Avengers (2012), Thor: The Dark World (2013), and Avengers: Age of Ultron (2015), and The Grand Duke in Cinderella (2015). Most recently he portrayed Boris Shcherbina in the HBO/Sky UK television miniseries Chernobyl (2019).