Born in San Francisco, California, on December 16, 1963, Bratt is the third of five children. He is the grandson of Broadway actor George Bratt and the son of a Peruvian Quechua Indian mother from Lima, who moved to the United States at age 14. His father, a sheet-metal worker, and his mother divorced in 1968. In 1969, Bratt’s mother, a Native American activist, participated in the takeover of Alcatraz Island. She brought along the five-year-old Benjamin and his brother and sisters. For over a year, they went to Alcatraz two or three times a week, Bratt has said. Bratt grew up in San Francisco, where he attended Lowell High School. Bratt showed no interest in acting until college. In 1986, he graduated with honors from the University of California, Santa Barbara. He then attended the American Conservatory Theatre in San Francisco, but did not complete the master’s program; instead he began his professional acting career at the Utah Shakespearean Festival. His first two pilots, Juarez and Lovers, Partners & Spies, did not sell, but in 1998 he starred in the short-lived Knightwatch on ABC as an ex-gang leader who becomes the leader of an anti-crime patrol. In 1990, Bratt joined another drama with a short life, NBC’s Nasty Boys, which was produced by Dick Wolf, who also created and produced Law & Order.
Bratt’s debut film roles came in 1990. First he was cast in Bright Angel and then in Chains of Gold, starring Joey Lawrence and John Travolta, in which he played a vicious drug dealer. Bratt also had supporting roles in One Good Cop (1991), Bound by Honor (1993), and Demolition Man (1993). Bratt gained Hollywood’s attention with two 1994 releases: In The River Wild, he portrayed a Native American ranger, and in Clear and Present Danger, he was the field officer for American soldiers sent by the CIA to infiltrate the Colombian countryside. Soon after, he was cast as the lead in the ABC miniseries James A. Michener’s Texas (1995). That year was also Bratt’s first as the conservative detective Rey Curtis on Law & Order. From 1990 until 1996, Bratt dated documentary filmmaker Monika. After actress Jennifer Esposito made a guest appearance on Law & Order in 1996, she and Bratt began a relationship that ended eight months later. Bratt’s high profile four-year long romance with the undisputed Queen of Hollywood, Julia Roberts, ended in July 2001. Roberts made a guest appearance on Law & Order in 1999 in the episode “Empire.”
In 1997, Bratt starred in and helped produce Follow Me Home, a low-budget film directed by his brother, Peter Bratt, and featuring Alfre Woodard and Salma Hayek. In 1999, Bratt decided to leave Law & Order. “I’ve felt like it was time to get back home to my family,” Bratt said. “How do you walk away from the best job in the world and a group of people that you’ve grown to love? It’s not easy, and it was an extremely difficult decision that I had to make.” On May 26, 1999, Bratt’s final episode was aired. He was named one of People’s “50 Most Beautiful” in the May 10, 1999, issue. In 2000, Bratt costarred with Madonna and Rupert Everett in The Next Best Thing. The following year, he played opposite Sandra Bullock in the romantic comedy Miss Congeniality and had a small role as part of a stellar ensemble cast of Traffic, which also included Benicio del Toro, Michael Douglas, and Catherine Zeta-Jones. Influenced by his mother’s politics and the way he was raised, Bratt’s own politics are left of center, and he has been active in Native American issues, including involvement in the American Indian Friendship House in Oakland, Californ.