Katheryn Winnick (December 17, 1977) is a Canadian actress. She is best known for her roles in Amusement (2008), Bones (2010), A Glimpse Inside the Mind of Charles Swan III (2012), Vikings (2013–present), and The Art of the Steal (2013).
Winnick was born in Etobicoke, Ontario and is of Ukrainian descent. She spoke Ukrainian as her first language and did not begin speaking English until she was eight years old. She began training in martial arts at age seven, and obtained her first black belt at 13. By age 21, she had started three martial arts schools.