He attended Belmont High School in Los Angeles, and at the age of 16, enlisted in the United States Army and became a paratrooper with the 11th Airborne Division.

In 1964, Fernandez was sentenced to 90 days in jail after pleading guilty to failing to file state tax returns in California for four years.

[2] Fernandez' film debut came in Second Chance (1953) in which his character, Rivera, fought a boxing match against star Robert Mitchum.

His character is based on that of William Jennings Gardner, American Indian member of the real-life Untouchables federal squad.

Fernandez has also appeared in dozens of TV and film roles in series such as Daniel Boone, Bonanza, Time Tunnel, Gunsmoke, Batman, Wagon Train, The Virginian, Have Gun – Will Travel, and Marcus Welby M.D., as well as theatrical films such as Fort Yuma, Target Zero, Second Chance (1953) with Robert Mitchum, Alaska Seas starring Robert Ryan (also 1953), Rose Marie with Fernando Lamas (1954), The Last Wagon (1956), Pork Chop Hill starring Gregory Peck (1959), Madigan with Richard Widmark (1968), Quicksilver (1986), and many more.