Peter Fernandez was born in New York City on January 29, 1927. He began his professional career as a child model for the John Robert Power Agency. Fernandez also had a career on Broadway and on radio. His radio appearances included roles on Mr. District Attorney, Let's Pretend, Gangbusters, My Best Girls, Superman, The Aldrich Family, The Sea Hound, and Suspense; Fernandez also appeared on many soap operas during the radio era. Near the end of World War II, he was drafted into the United States Army. After his discharge from the Army in 1946, Fernandez became a writer for radio and pulp fiction. He also wrote the children's book, Bedtime Stories From the Bible.

Fernandez began his involvement with anime in the 1960s. His first credits came in 1963, when he provided voices for the English dubs of Astro Boy and Gigantor (on the latter, Fernandez provided the voices for Buttons and Johnny). His other anime voice acting credits include: Marine Boy and Under Sea Boy Marine (as Dr. Mariner and Piper), Speed Racer (as Speed Racer and Racer X), Lupin III: The Secret of Mamo (as Arsene Lupin III, Daisuke Jigen, and President Jimmy Carter), Superbook, Kagaku Kyujotai Techno Voyager, Star Blazers: The Bolar Wars (as Mark Venture), The Enchanted Journey, and Kurokami the Animation (as Ryuujin Nagamine).

Fernandez served as a producer on Tobor the Eighth Man, wrote the English lyrics for the Speed Racer theme song, co-wrote the scripts for Speed Racer, and did some of the writing for Star Blazers: The Bolar Wars. He also served as a voice director for Gigantor, Marine Boy, Speed Racer, Under Sea Boy Marine, Star Blazers: The Bolar Wars, and The Enchanted Journey. Fernandez had a cameo in the 2008 live-action Speed Racer film as a race commentator, and also provided the voices for Spritle and Speed Racer in Speed Racer: The Next Generation. He has also had many other credits in animation and live-action over the course of his career, which included adapting, directing, and voicing English tracks for many foreign films. Fernandez has said that one of his favorite projects was serving as the voice director for Courage the Cowardly Dog; not only did he serve as the voice director for the series, he also provided the voice of Robot Randy.

Sadly, Peter Fernandez passed away from lung cancer on July 15, 2010 in Pomona, New York. He was 83 years old at the time of his passing.