He is of Peruvian ancestry. He is the brother of writer Peter Bratt and has four brothers. He moved from Lima to the United States at age 14. He married Julia Roberts in 1979 and then Soto in 2002. They have two children. Bratt is a staunch supporter and member of the San Francisco Bay Area House of Representatives of the American Indian Friendship Association. He worked in: Coco (2017), Despicable Me 2 (2013) and Snitch (2013).