Beau has an older brother Luke, (b. 15 February 1985) who plays semi-pro lacrosse and a younger sister Raeanna (b. 2 April 1992).
His father Bill is a Podiatrist from California. His mother Kelley, a Seattle native, is a full-time homemaker.
Beau Mirchoff was born in Seattle, Washington. Two days after he was born, he moved to his family's home in Victoria, British Columbia, Canada on Vancouver Island.