Chaves was born in Jacksonville, Florida, the son of a United States Marine Corps officer/drug enforcement agent father.He graduated from Mission Viejo High School in Mission Viejo, CA in 1969. He is part Cherokee on his mother's side. Chaves joined the army in 1970. He served 3 years in the army, with a tour of duty in Vietnam.
Chaves helped write the critically acclaimed stage drama Tracers. In the early 1980s, he began work as an actor taking on various soap opera roles until he gained a role in 1987 as Poncho in the science fiction film Predator. Soon afterward, his career received another boost with the role of Lt. Colonel Ironhorse in the television series War of the Worlds Chaves once calculated that the volume of fan mail he received outnumbered the rest of the cast members by a four or five to one ratio.
In the late 1990s, Chaves became the target of a stalker. To protect himself, his family and friends, he followed the advice of police by refraining from attending conventions and closing his official website.
Chaves has made few public appearances over the years since being stalked. He appeared at the Las Vegas Comic-Con in October 2003; in late 2006 he was photographed with Frances Fisher at the Flags of our Fathers premiere; he was a guest at the Chicagoland Entertainment Collectors Expo in October 2007; he appeared at the Gallifrey One convention in February 2007, and is scheduled to attend again in February 2008. His most recent acting appearance is in the soon-to-be-released film Lost Warrior: Left Behind and "Dark House".
In June 2009, he was present in Star Guest of "Collectormania" at the Stadium Way West, Milton Keynes, UK.
