Jim Beaver was born in Laramie, Wyoming, the son of Dorothy Adell (née Crawford) (1928-2019) and James Norman Beaver, Sr. (1924–2004), a minister. His father was of English and French heritage; the family name was originally de Beauvoir, and Beaver is a distant cousin of author and philosopher Simone de Beauvoir and Pennsylvania governor General James A. Beaver. Beaver's mother has Cherokee, German, and Scottish ancestry, and is a descendant of three-time U.S. Attorney General John J. Crittenden.
He is most familiar to worldwide audiences as Bobby Singer in Supernatural. He also played Whitney Ellsworth on the HBO Western drama series Deadwood, which brought him acclaim and a Screen Actors Guild Awards nomination for Ensemble Acting, and Sheriff Shelby Parlow on the FX series Justified.