Ernie Reyes is the son of Filipino immigrants Ernesto and Valentina Reyes, who came to California in the 1920s. He grew up in Salinas, California, and started working in the fields when he was 12 years old. He majored in Business administration at San Jose State University, where he met Tony Thompson. In 1966 he began studying martial arts with Tang Soo Do, continuing through his years at San Jose State. He then studied Tae Kwon Do. By the early 70s, he was studying other martial arts, including Boxing, Kickboxing, Escrima, knife, and Wu Shu. In the mid-1970s, he competed in karate. He won the US National Tae Kwon Do championship in 1977, followed by a bronze at the 1977 World Taekwondo Championships.