This list curates 42 exceptional science fiction books available for free download or online reading. It includes seminal bestsellers that defined the genre and modern hits released under Creative Commons.
1. Frankenstein; Or, The Modern Prometheus (HTML)
Author: Mary Shelley
Often cited as the first true science fiction novel, this 1818 masterpiece tells the tragic story of Victor Frankenstein and the sentient creature he constructs from corpses. It is a profound exploration of scientific responsibility, alienation, and what it means to be human.
2. Twenty Thousand Leagues Under the Sea (HTML/Ebook)
Author: Jules Verne
A globally successful adventure that introduced the world to Captain Nemo and his advanced submarine, the Nautilus. This classic combines underwater exploration with a prescient vision of technology and a gripping psychological battle of wills.
3. The Time Machine (HTML)
Author: H.G. Wells
The novella that popularized the concept of time travel using a vehicle, sending its protagonist to the year 802,701 AD. It vividly contrasts the gentle, childlike Eloi with the savage, subterranean Morlocks, serving as a biting social commentary on class division.
4. The War of the Worlds (HTML)
Author: H.G. Wells
One of the most influential alien invasion stories ever written, detailing a Martian attack on Southern England. It remains a terrifying and fast-paced survival story that established the blueprint for the entire “invasion” subgenre.
5. A Journey to the Center of the Earth (HTML)
Author: Jules Verne
Professor Lidenbrock and his nephew Axel descend into an Icelandic volcano to discover a vast subterranean world of prehistoric creatures and oceans. It is the quintessential scientific adventure story, filled with wonder and 19th-century geological speculation.
6. Little Brother (PDF/HTML)
Author: Cory Doctorow
A modern New York Times bestseller about a teenage hacker who fights back against the Department of Homeland Security after being wrongly detained. It is a techno-thriller that serves as a primer on digital privacy, encryption, and civil liberties.
7. The Strange Case of Dr. Jekyll and Mr. Hyde (HTML)
Author: Robert Louis Stevenson
A defining gothic novella that explores the duality of human nature through a scientist’s experiment to separate his good and evil sides. While often seen as horror, its premise of chemical transformation makes it a cornerstone of “mad scientist” sci-fi.
8. A Princess of Mars (HTML/Ebook)
Author: Edgar Rice Burroughs
The pulp classic that introduced John Carter, a Civil War veteran transported to a dying Mars (Barsoom). This sword-and-planet adventure is packed with four-armed green aliens, daring rescues, and the romance of Dejah Thoris.
9. The Invisible Man (HTML)
Author: H.G. Wells
The story of Griffin, a scientist who discovers how to make himself invisible but fails to reverse the process, driving him to megalomania and madness. It is a tense thriller that examines the corrupting power of unchecked scientific capability.
10. The Lost World (HTML)
Author: Arthur Conan Doyle
Professor Challenger leads an expedition to a South American plateau where dinosaurs and prehistoric ape-men still survive. This rollicking adventure set the standard for the “lost world” trope and inspired countless films, including Jurassic Park.
11. Blindsight (HTML)
Author: Peter Watts
A hard sci-fi cult classic about a crew of transhuman misfits sent to investigate an alien presence at the edge of the solar system. It is a dark, intellectually dense novel that questions the nature of consciousness and intelligence.
12. On Basilisk Station (HTML/Ebook)
Author: David Weber
The first book in the massively popular Honor Harrington series, introducing a brilliant female starship commander exiled to a backwater outpost. It blends Napoleonic-era naval tactics with high-tech space opera in a gripping military sci-fi tale.
13. 1632 (HTML/Ebook)
Author: Eric Flint
A modern alternate history hit where a small West Virginia mining town is transported through time to 17th-century Germany during the Thirty Years’ War. The clash of modern American technology and ideals with Renaissance Europe creates a fascinating society-building story.
14. The Island of Doctor Moreau (HTML)
Author: H.G. Wells
A shipwrecked man discovers a remote island where a vivisectionist is surgically uplifting animals into painful, semi-human forms. It is a disturbing and philosophical inquiry into the limits of scientific ethics and the beast within man.
15. Flatland: A Romance of Many Dimensions (HTML/Ebook)
Author: Edwin A. Abbott
A unique satirical novella set in a two-dimensional world occupied by geometric figures, narrated by a Square who visits Spaceland (3D). It is both a brilliant mathematical thought experiment and a sharp critique of Victorian social hierarchy.
16. Accelerando (HTML)
Author: Charles Stross
A dizzying chronicle of three generations of a family living through the technological singularity, where AI surpasses human intelligence. It is packed with dense concepts like upload economics, solar system dismantling, and digital existence.
17. Looking Backward: 2000–1887 (HTML)
Author: Edward Bellamy
A 19th-century Bostonian falls asleep and wakes up in the year 2000 to find a socialist utopia where capitalism has been replaced by a cooperative commonwealth. It was the third-bestselling book of its time and sparked a massive political movement.
18. A Connecticut Yankee in King Arthur’s Court (HTML)
Author: Mark Twain
An engineer from 19th-century America travels back to Camelot and attempts to modernize medieval England with fireworks, telephone lines, and explosives. It is a satirical masterpiece that contrasts modern technology with feudal superstition.
19. The Mysterious Island (HTML)
Author: Jules Verne
Five Americans escape the Civil War in a balloon and crash on an uncharted island, where they must use their scientific knowledge to rebuild civilization from scratch. It is the ultimate “competence porn” survival story, linking back to 20,000 Leagues.
20. The Gods of Mars (HTML)
Author: Edgar Rice Burroughs
The second Barsoom book returns John Carter to Mars, where he battles the false religion of the Therns to save his wife and son. It expands the planetary lore and features non-stop pulp action and aerial battles.
21. First Men in the Moon (HTML)
Author: H.G. Wells
Two men invent a gravity-defying substance called “Cavorite” and travel to the moon, discovering a sophisticated insect-like civilization called the Selenites. It blends scientific speculation with a satirical look at specialized societies.
22. Herland (HTML/Ebook)
Author: Charlotte Perkins Gilman
Three male explorers discover an isolated society composed entirely of women who reproduce asexually and have built a peaceful, conflict-free utopia. It is a feminist classic that challenges traditional gender roles and societal structures.
23. Metropolis (HTML/Ebook)
Author: Thea von Harbou
The novelization of the legendary silent film, depicting a futuristic city divided between wealthy thinkers in skyscrapers and oppressed workers underground. It features the iconic “Maschinenmensch” robot and explores themes of revolution and reconciliation.
24. We (HTML/Ebook)
Author: Yevgeny Zamyatin
The original dystopian novel that inspired Orwell’s 1984, set in a totalitarian One State where citizens are numbers and live in glass houses. It is a powerful critique of conformity and the suppression of the individual imagination.
25. Anthem (HTML)
Author: Ayn Rand
A novella set in a dark future where the word “I” has been erased and technology has regressed, following one man’s rediscovery of electricity and individuality. It is a concise, parabolic story about the importance of the ego and the self.
26. The Iron Heel (HTML)
Author: Jack London
A dystopian novel written from the perspective of a future scholar looking back on the rise of a fascist oligarchy in the United States. It is remarkably prescient in its prediction of 20th-century political upheavals and class warfare.
27. Deathworld (HTML)
Author: Harry Harrison
Jason dinAlt, a gambler and psychic, travels to the deadliest planet in the galaxy where the flora and fauna actively evolve to kill humans. It is a fast-paced action novel with a clever ecological twist on why the planet is so hostile.
28. Little Fuzzy (HTML)
Author: H. Beam Piper
A prospector on a colony planet discovers a small, cute species and must prove they are sapient to stop a corporation from exploiting their land. It is a charming and legally-focused sci-fi story that debates what defines “people.”
29. The Machine Stops (HTML)
Author: E.M. Forster
A stunningly prophetic short story from 1909 describing a future where humanity lives in isolation underground, communicating only through video screens and worshipping the “Machine.” It predicts the internet, social isolation, and the fragility of technological dependence.
30. A Hymn Before Battle (HTML/Ebook)
Author: John Ringo
The first book in the Legacy of the Aldenata series, where Earth is enlisted by galactic aliens to fight a horde of centaur-like predators. It is gritty military sci-fi focusing on infantry combat and the geopolitical consequences of alien contact.
31. Starfish (HTML)
Author: Peter Watts
Bio-engineered workers adapted to survive high pressure are stationed at a geothermal power plant on the ocean floor, but their unstable psyches begin to fray. It is a claustrophobic, deep-sea thriller exploring trauma and biology.
32. Down and Out in the Magic Kingdom (PDF/HTML)
Author: Cory Doctorow
Set in a post-scarcity future where reputation is currency (“Whuffie”), a man tries to restore the Haunted Mansion at Disney World while battling a rival group. It is a quirky, inventive look at the “reputation economy” and immortality.
33. Triplanetary (HTML)
Author: E.E. “Doc” Smith
The prequel to the famous Lensman series, spanning cosmic history as two ancient alien races manipulate humanity towards an ultimate conflict. It defines the “space opera” scale with super-weapons, galactic patrols, and eugenics.
34. The Skylark of Space (HTML)
Author: E.E. “Doc” Smith
One of the first novels to feature interstellar travel, following a scientist who discovers a drive that allows him to explore the galaxy and battle a rival genius. It is the archetype of the “superscience” adventure story.
35. The Night Land (HTML/Ebook)
Author: William Hope Hodgson
A difficult but rewarding classic set millions of years in the future where the sun has died and the last humans live in a giant pyramid surrounded by monsters. It is a masterwork of atmosphere, horror, and dying-earth fantasy.
36. The House on the Borderland (HTML/Ebook)
Author: William Hope Hodgson
A man’s recluse home becomes a gateway to other dimensions and a siege point for swine-like monsters, eventually witnessing the end of the solar system. It is a psychedelic cosmic horror story that influenced H.P. Lovecraft.
37. Armageddon 2419 A.D. (HTML)
Author: Philip Francis Nowlan
The novella that introduced Anthony “Buck” Rogers, a man who wakes up 500 years in the future to find America occupied by the Han Empire. It is the foundational text for the Buck Rogers comic strips and serials.
38. The Poison Belt (HTML)
Author: Arthur Conan Doyle
Professor Challenger returns to witness the Earth passing through a belt of poisonous ether that seemingly kills all human life. It is a “cosmic disaster” story focusing on a small group observing the end of the world from a sealed room.
39. Makers (PDF/HTML)
Author: Cory Doctorow
A sprawling novel about the “maker” movement, following hackers and engineers who try to reinvent the economy from junk in a decaying America. It is a near-future look at innovation, copyright law, and the spirit of tinkering.
40. Plague Ship (HTML)
Author: Andre Norton
A Free Trader starship crew is banned from ports after being accused of spreading a deadly plague and must solve the mystery to clear their names. It is a solid “space trucker” adventure from the Grand Dame of Science Fiction.
41. The Coming Race (HTML/Ebook)
Author: Edward Bulwer-Lytton
A traveler discovers a superior subterranean civilization, the Vril-ya, who control a powerful energy force called “Vril.” It is an early example of dystopian utopianism and occult sci-fi that culturally impacted the late 19th century.
42. The Warrior’s Apprentice (HTML/Ebook)
Author: Lois McMaster Bujold
Young Miles Vorkosigan, physically disabled in a warrior culture, accidentally creates his own mercenary fleet to prove his worth. This is a witty, character-driven space opera that launches one of the most beloved series in modern sci-fi.