Alexander "Alex" Ludwig is a Canadian actor and singer. He first began his career as a child, and then received recognition as a teenager for starring in the films The Seeker: The Dark Is Rising (2007) and Race to Witch Mountain (2009). He shot to fame for starring as Cato in The Hunger Games (2012). He is also known for his supporting roles as Shane Patton in Lone Survivor (2013), and Dorn in Bad Boys for Life (2020). He also starred as Bjorn in the History Channel series Vikings (2014–2020).