Born in El Paso, Texas, Roddenberry grew up in Los Angeles, where his father was a police officer.
Roddenberry flew 89 combat missions in the Army Air Forces during World War II, and worked as a commercial pilot after the war. Later, he followed in his father's footsteps and joined the Los Angeles Police Department, where he also began to write scripts for television.
Roddenberry majored in police science at Los Angeles City College, and became interested in aeronautical engineering. He obtained a pilot's license through the United States Army Air Corps-sponsored Civilian Pilot Training Program. He enlisted with the USAAC on December 18, 1941, and graduated from the USAAC on August 5, 1942, when he was commissioned as a second lieutenant.
He was posted to Bellows Field, Oahu, to join the 394th Bomb Squadron, 5th Bombardment Group, of the Thirteenth Air Force, flying B-17E-BO, 41-2463, "Yankee Doodle", after his piloting days were over as a result of crashing on Vanuatu, he spent the remainder of his military career in the United States, as a plane crash investigator. He was involved in another plane crash, this time as a passenger and awarded the Distinguished Flying Cross and the Air Medal.
In 1945, Roddenberry began flying for Pan Am, including routes from New York to Johannesburg or Calcutta, the two longest Pan Am routes at the time. His third crash was while on the Clipper Eclipse in June of 1947.
The plane came down in the Syrian Desert, and Roddenberry, who took control as the ranking flight officer, suffered two broken ribs but was able to drag injured passengers out of the burning plane and led the group to get help. He resigned from Pan Am in 1948, and pursued his dream of writing, particularly for the new medium of television.
Roddenberry applied for a position with the Los Angeles Police Department in Jan 1949, and spent his first 16 months in the traffic division before being transferred to the newspaper unit. This became the Public Information Division and Roddenberry became the Chief of Police's speech writer.
In 1985, he became the first TV writer with a star on the Hollywood Walk of Fame