| Lest Darkness Fall | 1941 | Alternate history |
| The Great Monkey Trial | 1968 | |
| Solomon's Stone | 1957 | Fantasy |
| The Bronze God of Rhodes | 1960 | Historical novel |
| An Elephant for Aristotle | 1958 | Historical novel |
| The Dragon of the Ishtar Gate | 1961 | Historical novel |
| The Golden Wind | 1969 | Historical novel |
| Energy and Power | 1962 | Science |
| Engines | 1959 | |
| Elephant | 1964 | |
| Man and Power | 1961 | |
| Darwin and His Great Discovery | 1972 | |
| The Day of the Dinosaur | 1968 | |
| The Arrows of Hercules | 1965 | Historical novel |
| The Heroic Age of American Invention | 1961 | |
| The Ancient Engineers | 1963 | Philosophy |
| Ancient Ruins and Archaeology | 1964 | |
| The Story of Science in America | 1967 | Science |
| Spirits, Stars, and Spells | 1966 | History |
| The Ragged Edge of Science | 1980 | |
| Great Cities of the Ancient World | 1972 | History |
| Lost Continents | 1954 | |
| The Fringe of the Unknown | 1983 | Science |
| Lands Beyond | 1952 | History |
| Lovecraft: a Biography | 1975 | Biography |
| Dark Valley Destiny | 1983 | Biography |
| Literary Swordsmen and Sorcerers | 1976 | |
| The Evolution of Naval Weapons | 1947 | |
| The Miscast Barbarian | 1975 | Biography |
| The Undesired Princess | 1951 | Fantasy |
| The Honorable Barbarian | | Fantasy |
| The Goblin Tower | | Fantasy |
| The Clocks of Iraz | | Fantasy |
| Footprints on Sand | 1981 | Fantasy |
| The Queen of Zamba | 1977 | Science Fiction |
| Rubber Dinosaurs and Wooden Elephants | 1996 | |
| Land of Unreason | 1942 | Fantasy |
| The Carnelian Cube | | Fantasy |
| Time and Chance: an Autobiography | 1996 | Biography |
| Scribblings | 1972 | Science Fiction |
| The Hand of Zei | 1981 | Science Fiction |
| The Hostage of Zir | 1977 | Science Fiction |
| Inventions and Their Management | 1937 | |
| The Best of L. Sprague de Camp | 1978 | Fantasy |
| A Gun for Dinosaur and Other Imaginative Tales | 1963 | Science Fiction |
| The Wheels of If and Other Science Fiction | 1948 | Science Fiction |
| Sprague de Camp's New Anthology of Science Fiction | 1953 | Science Fiction |
| The Virgin & the Wheels | 1976 | Science Fiction |
| Demons and Dinosaurs | 1970 | Poetry |
| Phantoms and Fancies | 1972 | Poetry |
| Heroes and Hobgoblins | 1981 | Poetry |
| Aristotle and the Gun and Other Stories | 2002 | Fantasy |
| Rivers of Time | 1993 | Science Fiction |
| Years in the Making: the Time-Travel Stories of L. Sprague de Camp | 2005 | Science Fiction |
| The Purple Pterodactyls | 1980 | Fantasy |
| The Reluctant Shaman and Other Fantastic Tales | 1970 | Fantasy |
| Tales from Gavagan's Bar | 1953 | Fantasy |
| The Tritonian Ring and Other Pusadian Tales | | Fantasy |
| The Continent Makers and Other Tales of the Viagens | 1953 | Science Fiction |
| Divide and Rule | 1948 | Science Fiction |
| Blond Barbarians and Noble Savages | 1975 | Biography |
| Conan and the Spider God | | Sword and sorcery |
| Antarctic Conquest | 1949 | |
| Conan the Liberator | | Sword and sorcery |
| The Ape-Man Within | 1995 | Science |
| Conan the Barbarian | | Sword and sorcery |
| The Glory That Was | | Science Fiction |
| Conan of the Isles | | Fantasy |
| Conan the Avenger | | Fantasy |
| The Return of Conan | | Sword and sorcery |
| Genus Homo | 1950 | Science Fiction |
| Conan of Aquilonia | | Fantasy |
| Science-Fiction Handbook | 1953 | |
| Conan of Cimmeria | | Fantasy |
| Conan the Adventurer | | Fantasy |
| Conan the Freebooter | | Fantasy |
| Conan | | Fantasy |
| Conan the Usurper | | Fantasy |
| Conan the Wanderer | | Fantasy |
| Conan the Buccaneer | | Sword and sorcery |
| Conan the Swordsman | | Fantasy |
| Tales of Conan | | Fantasy |
| To Quebec and the Stars | 1976 | |
| The Incorporated Knight | | Fantasy |
| The Pixilated Peeress | | Fantasy |
| Sagas of Conan | | Fantasy |
| The Virgin of Zesh | 1976 | Science Fiction |
| The Virgin of Zesh & The Tower of Zanid | | Science Fiction |
| The Treasure of Tranicos | | Fantasy |
| The Flame Knife | | Fantasy |
| The Conan Chronicles | | Fantasy |
| The Conan Chronicles 2 | | Fantasy |
| The Reluctant King | | Fantasy |
| The Fallible Fiend | | Fantasy |
| The Incomplete Enchanter | 1941 | Fantasy |
| The Castle of Iron | 1950 | Fantasy |
| Wall of Serpents | 1960 | Fantasy |
| The Conan Reader | | Sword and sorcery |
| The Conan Grimoire | | Essay |
| The Conan Swordbook | | Essay |