Dean's first film was 1988's Plain Clothes. He made his big break a year later, cast as a bad ex-boyfriend in Say Anything... starring John Cusack. His third film, the 1991 crime drama Billy Bathgate, cast him opposite Nicole Kidman, Dustin Hoffman and Bruce Willis. Although the film did not do well at the box office, Dean won positive reviews for his performance.

Dean moved to New York City to pursue an acting career. After two years, a friend introduced him to an agent, and he began appearing in stage plays in New York. He won a Theatre World Award in 1989 for his Off Broadway debut in the play Amulets Against the Dragon Forces at the Circle Repertory Company. He is a Playwright and one of Academy Award-winning Screenwriter John Patrick Shanley's favorite actors, having appeared in many of the author's plays, notably 4 Dogs and a Bone and Beggars in the House of Plenty.

Much of his acting career, however, has been in supporting roles. His films include Apollo 13 (1995), How to Make an American Quilt (1995), Gattaca (1997), Enemy of the State (1998) and Space Cowboys (2000). Dean has appeared in a number of independent films (such as The War Bride and The Poker Club) and several well-received television miniseries (such as The Bronx Is Burning). He has also played Russ, the brother of Temperance "Bones" Brennan on the TV series Bones. He also had a recurring role on the 2010 crime drama Terriers. In 2011, Dean starred in the made-for-television movie Who Is Simon Miller? The film, which aired on NBC, was financed by Procter & Gamble and Walmart as one of their quarterly "Family Movie Night" films. Each film is designed to present wholesome values with almost no violence, sex, or drug use.

Dean has supported filmmakers behind the scenes as well. In 1999, he was a juror for the third annual Shorts International Film Festival.

Loren Dean Jovicic was born in Las Vegas, Nevada. His mother worked as a family and marriage counselor, and his father was in the clothing Business. His parents divorced when he was a small child. His mother won custody of Loren, and the family moved to Los Angeles, California. When visiting his father, the two often went to the movies—which Dean says led to his love of film. His childhood was a difficult one, and he ran away from home when he was 16 years old. He graduated from Santa Monica High School in Santa Monica, California, in 1986.