Gustaf Caspar Orm Skarsgård is a Swedish actor. He is known for his roles in Evil (2003), The Way Back (2010), Kon-Tiki (2012), and Oppenheimer (2023). He also appeared in the HBO TV series Westworld (2018), as Merlin in the Netflix TV series Cursed (2020), and as Floki in the History Channel series Vikings (2013–2020).

Evil is a 2003 Swedish drama film which was released to cinemas in Sweden on 26 September 2003, directed by Mikael Håfström, based on Jan Guillou's semi-autobiographical novel of the same name from 1981, and starring Andreas Wilson, Henrik Lundström and Gustaf Skarsgård. The film is set in a private boarding school in the late-1950s with institutional violence as its theme.