Diego Klattenhoff is a Canadian actor best known for his starring role as Mike Callahan in the medical drama television series Mercy, from 2009-2010.
He also starred as Mike Faber on Homeland and has a starring role as Donald Ressler, a veteran FBI field agent who's been tracking Reddington for the bulk of his career and whose greatest asset is his single-minded, almost obsessive devotion to his work, in the crime drama television series The Blacklist..
Klattenhoff was born outside of New Glasgow in Nova Scotia and moved to Toronto to pursue acting at the age of 19. He studied in theatre workshops for a number of years, while bussing tables, bartending and adapting to life in Toronto.
Klattenhoff studied with some of Canada's most respected acting coaches, including David Rotenberg, Bruce Clayton and Rae Ellen Bodie, and eventually his dedication and persistence paid off.
His first big break was in Mean Girls, starring Lindsey Lohan and Rachel McAdams. Mark Waters directed this cult favourite.
Additional credits include guest starring roles on numerous films, movies of the week, and television series such as Smallville, Psych and Supernatural, as well as recurring roles on Men in Trees and 24.
Klattenhoff also appeared as a series regular on Canada's CTV's Whistler and starred in JJ Abrams' pilot, Hope Against Hope.
Before acting, Klattenhoff's dream was to become a professional baseball player. When time permits, he still loves to play on the diamond as well as indulge in golf, football, hockey and swimming.
Klattenhoff divides his time between Toronto, Vancouver, and his new home in Los Angeles.