Hafþór Júlíus Björnsson (Icelandic pronunciation: [ˈhafθour ˈjuːliʏs ˈpjœrtnsːɔn]; born November 26, 1988) is an Icelandic professional strongman and actor. He is the current World's Strongest Man and is the first person to have won the Arnold Strongman Classic, Europe's Strongest Man and World's Strongest Man in the same calendar year. He plays Gregor "The Mountain" Clegane in the HBO series Game of Thrones. He also is a former professional basketball player.
Born in Reykjavík, Hafþór began his basketball career in 2004 with Division I team Breiðablik, moving to FSu in 2005. He transferred to Premier League side KR in 2006 before returning to FSu in 2007. He helped FSu to promotion from Division I to the Premier League but his career was cut short in 2008 due a recurrent ankle injury. He subsequently began his strongman career.
Hafþór won the Strongest Man in Iceland event in 2010, and won Iceland's Strongest Man in 2011. He won Europe's Strongest Man in 2014, a feat he repeated in 2015, 2017, and 2018. He won silver at the 2017 Arnold Strongman Classic, improving to gold in 2018. He competed in his first World's Strongest Man in 2011, placing sixth. He won three bronze and three silver medals in his next six attempts before being crowned champion in 2018.