- Douglas Adams (The Hitchhiker's Guide to the Galaxy)
Jumping from career to career in his early life including (as per his account) “hospital porter, barn builder, chicken shed cleaner, bodyguard, radio producer and script editor of Doctor Who” as well as, of course, a hitchhiker, Adams had the script for the radio play The Hitchhiker’s Guide to the Galaxy bought and produced while he was writing for Doctor Who, and he eventually (under duress) adapted it into a novel. During his later career, he was also responsible for several computer games, performed with Pink Floyd, and worked as an environmental activist (his book Last Chance to See details some of his work in this line).
- Isaac Asimov (Foundation, I, Robot)
Asimov received his Ph.D in biochemistry and worked as a researcher and as a professor at Boston University while he wrote his books (the first being published in 1950) until he became a full-timer writer eight years later. At one point, he published a paper on "The Endochronic Properties of Resublimated Thiotimoline", a substance so water-soluble that it would dissolve as much as 1.3 seconds before water was added.
- Alfred Bester (The Stars my Destination, The Demolished Man)
Bester wrote scripts for comics, radio, and television throughout his career, eventually becoming the literary editor for Holiday magazine, for whom he had written travel articles. He was a major contributor to a number of superheroes’ canons, including (for example) being the author of the Green Lantern Oath.
- Ray Bradbury (The Martian Chronicles, Fahrenheit 451)
Because his talent as a writer was recognized early (while he was in high school, in fact) Bradbury spent his entire career as a writer of books and screenplays.
- Orson Scott Card (Ender's Game)
Card, in his early life, was a missionary for the Church of Latter-day Saints, the leader of a theater company (and the salesman for their tickets), and staff editor for The Ensign, a magazine.
- Arthur C. Clarke (2001: A Space Odyssey)
Clarke began his career as an auditor in the British Civil Service. He become an officer in the RAF during World War II, which propelled him into a career in radar, satellites, and similar pursuits. It is, in fact, arguable that his contributions to science are as important as his contributions to science fiction.
- Michael Crichton (The Andromeda Strain, Jurassic Park)
During his schooling, Crichton experimented with studying writing, anthropology, and medicine. His first novel (The Andromeda Strain) was published during his last year in medical school and quickly sold to be adapted into a movie, and he only had to spend two years using his degree in medicine before becoming a professional writer. He has since run a software company, programmed and published a computer game, and penned biographies.
- Philip K. Dick (Do Androids Dream of Electric Sheep?, A Scanner Darkly)
Dick, emerging from a wholly depressed and dark childhood, worked for several years in retail before being encouraged to start submitting his short stories to science fiction pulps and eventually into novelism.
- William Gibson (Neuromancer, The Difference Engine)
Gibson began his career as a writer and continued his career as a writer, graduating college with a bachelor’s degree in English literature and publishing the seminal Neuromancer as his first novel.
- Robert A. Heinlein (The Moon is a Harsh Mistress, Stranger in a Strange Land)
Heinlein graduated from the Naval Academy in Annapolis, Maryland, preparing to have a military career, but was forced out of service after five years because of tuberculosis. He went through a number of jobs including real estate and as a political campaigner before he discovered himself as a writer.
- Frank Herbert (Dune)
Herbert was a journalist and speechwriter (as well as serving in the Navy as a photographer during World War II) before he began to write short stories for science fiction magazines.
- Ursula K. Le Guin (The Earthsea Trilogy, The Left Hand of Darkness)
Despite a fantastically promising education and upbringing, Le Guin worked as a secretary at Emory University before she began to write science fiction novels during the 1960s. Today, she lectures at colleges and other venues in addition to her writing.
- Larry Niven (Ringworld, The Mote in God's Eye)
Niven dropped out of the California Institute of Technology due to his love of science fiction and inability to stop reading it, and later dropped out of graduate school at UCLA in order to begin writing science fiction. He has written scripts for several television shows, including Star Trek.
- Theodore Sturgeon (More Than Human)
Sturgeon’s first career aspiration was to be an acrobat, unfortunately foiled due to a heart defect. Although he did become a successful writer, he had a startling number of jobs throughout his career, as he was often plagued by writer’s block. These included selling magazines door-to-door, driving a bulldozer, serving in the Merchant Marines, editing several magazines, writing for Star Trek, working as a dockworker, and managing a hotel.
- Jules Verne (From the Earth to the Moon, 20,000 Leagues Under the Sea)
As a child, Verne ran away from home and became a cabin boy on a merchant ship. Returning home soon after (as he was caught), he eventually went to Paris to study law. Finding it boring, he began to write plays, which led to his father cutting off the money Jules was being sent to live on. He began writing novels to pay for his expenses, which had become unsupportable without money.
- H. G. Wells (The Time Machine, The War of the Worlds)
At the age of 14, Wells was apprenticed as a draper during the course of three years. After that, he became a teacher at a grammar school until winning a scholarship to the Normal School of Science and taking biology courses from T. H. Huxley. After dropping out, he returned to teaching and eventually made his way to writing.