Hafþór Júlíus Björnsson

Hafþór Júlíus Björnsson (born November 26, 1988, in Reykjavík, Iceland) is an Icelandic screen artist best known for bringing imposing physicality and quiet menace to the roles he chooses. Before acting, he competed at elite levels as a professional strongman and also spent time as a professional basketball player—experiences that shaped the larger-than-life presence audiences recognize instantly.

Björnsson gained worldwide fame as Ser Gregor “The Mountain” Clegane in HBO’s Game of Thrones, a performance that turned him into a pop-culture icon and led to high-profile appearances such as Game of Thrones The IMAX Experience. His screen work often leans into his formidable stature while adding personality and control behind the power.

Beyond fantasy television, he has expanded into action cinema with credits including Kickboxer: Retaliation as Mongkut and Operation Ragnarok as Big John. He also appears as himself in multiple sports and event projects, from Born Strong to Eddie Hall: The Beast v The Mountain, blending athletic stardom with on-camera storytelling.

Whether portraying a feared warrior or stepping into the spotlight as a competitor, Björnsson continues to bridge strength sports and acting with international appeal.