Brian Krause was born in El Toro, California on February 1, 1969 to Alice and Jeff Krause. He is the younger of their two children; his older brother is named Patrick. Brian grew up in Southern California and took his first acting class with R.J. Adams at The Actors Workshop while in junior high, as a way to avoid a bully in physical education class. In his teens, he studied karate and attended El Toro High School, where he graduated in 1987. He continued his education at Orange Coast College, where he played and lettered in soccer, and scored four goals as a midfielder and forward. He later had a child.
Krause landed his first role in 1989 as a student in the TV series TV 101. He then starred in the made-for-TV-movie "Match Point", the CBS Schoolbreak Special "American Eyes", and "An American Summer", before landing his first major role as Richard Lestrange in the film "Return to the Blue Lagoon" (1991). He was a co-star in the "Bandit" series prior to his most notable role of Leo Wyatt, in The WB Network series "Charmed" (1998–2006).
Krause originally auditioned for the role of Andy Trudeau but was cast as Piper's handyman/whitelighter love interest. Due to budget restrictions in the eighth season (2005–06), he only appeared in the first 10 episodes and last two episodes. After "Charmed", he has appeared in made-for-TV-movies and TV shows such as "Mad Men" and "The Closer". He also lent his voice and image to portray a minor character (Clem Feeney) in the videogame "L.A. Noire", and he appeared in the YouTube video series "Chad Vader", in Season 4, Episode 4: "The Return of Brian", as himself, a former employee of Empire Market.